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Remove target for d* #2213 #2280
Conversation
🔍 Vulnerabilities of
|
digest | sha256:25433acac07b882acd539ea05ea7ae736c56120baa146d7999e622a2fd730e7b |
vulnerabilities | |
platform | linux/amd64 |
size | 15 MB |
packages | 21 |
stdlib
|
Affected range | <1.19.9 |
Fixed version | 1.19.9 |
Description
Not all valid JavaScript whitespace characters are considered to be whitespace. Templates containing whitespace characters outside of the character set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also contain actions may not be properly sanitized during execution.
Affected range | <1.19.8 |
Fixed version | 1.19.8 |
Description
Templates do not properly consider backticks (`) as Javascript string delimiters, and do not escape them as expected.
Backticks are used, since ES6, for JS template literals. If a template contains a Go template action within a Javascript template literal, the contents of the action can be used to terminate the literal, injecting arbitrary Javascript code into the Go template.
As ES6 template literals are rather complex, and themselves can do string interpolation, the decision was made to simply disallow Go template actions from being used inside of them (e.g. "var a = {{.}}"), since there is no obviously safe way to allow this behavior. This takes the same approach as github.com/google/safehtml.
With fix, Template.Parse returns an Error when it encounters templates like this, with an ErrorCode of value 12. This ErrorCode is currently unexported, but will be exported in the release of Go 1.21.
Users who rely on the previous behavior can re-enable it using the GODEBUG flag jstmpllitinterp=1, with the caveat that backticks will now be escaped. This should be used with caution.
Affected range | >=1.17.0-0 |
Fixed version | 1.17.7 |
Description
Some big.Int values that are not valid field elements (negative or overflowing) might cause Curve.IsOnCurve to incorrectly return true. Operating on those values may cause a panic or an invalid curve operation. Note that Unmarshal will never return such values.
Affected range | <1.19.10 |
Fixed version | 1.19.10 |
Description
On Unix platforms, the Go runtime does not behave differently when a binary is run with the setuid/setgid bits. This can be dangerous in certain cases, such as when dumping memory state, or assuming the status of standard i/o file descriptors.
If a setuid/setgid binary is executed with standard I/O file descriptors closed, opening any files can result in unexpected content being read or written with elevated privileges. Similarly, if a setuid/setgid program is terminated, either via panic or signal, it may leak the contents of its registers.
Affected range | <1.17.11 |
Fixed version | 1.17.11 |
Description
On Windows, executing Cmd.Run, Cmd.Start, Cmd.Output, or Cmd.CombinedOutput when Cmd.Path is unset will unintentionally trigger execution of any binaries in the working directory named either "..com" or "..exe".
Affected range | <1.20.0 |
Fixed version | 1.20.0 |
Description
Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time. RSA blinding was applied to prevent timing attacks, but analysis shows this may not have been fully effective. In particular it appears as if the removal of PKCS#1 padding may leak timing information, which in turn could be used to recover session key bits.
In Go 1.20, the crypto/tls library switched to a fully constant time RSA implementation, which we do not believe exhibits any timing side channels.
Affected range | <1.20.10 |
Fixed version | 1.20.10 |
Description
A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing.
With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection.
This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2.
The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.
Affected range | <1.19.8 |
Fixed version | 1.19.8 |
Description
Calling any of the Parse functions on Go source code which contains //line directives with very large line numbers can cause an infinite loop due to integer overflow.
Affected range | <1.19.8 |
Fixed version | 1.19.8 |
Description
Multipart form parsing can consume large amounts of CPU and memory when processing form inputs containing very large numbers of parts.
This stems from several causes:
- mime/multipart.Reader.ReadForm limits the total memory a parsed multipart form can consume. ReadForm can undercount the amount of memory consumed, leading it to accept larger inputs than intended.
- Limiting total memory does not account for increased pressure on the garbage collector from large numbers of small allocations in forms with many parts.
- ReadForm can allocate a large number of short-lived buffers, further increasing pressure on the garbage collector.
The combination of these factors can permit an attacker to cause an program that parses multipart forms to consume large amounts of CPU and memory, potentially resulting in a denial of service. This affects programs that use mime/multipart.Reader.ReadForm, as well as form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue.
With fix, ReadForm now does a better job of estimating the memory consumption of parsed forms, and performs many fewer short-lived allocations.
In addition, the fixed mime/multipart.Reader imposes the following limits on the size of parsed forms:
- Forms parsed with ReadForm may contain no more than 1000 parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxparts=.
- Form parts parsed with NextPart and NextRawPart may contain no more than 10,000 header fields. In addition, forms parsed with ReadForm may contain no more than 10,000 header fields across all parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxheaders=.
Affected range | <1.19.8 |
Fixed version | 1.19.8 |
Description
HTTP and MIME header parsing can allocate large amounts of memory, even when parsing small inputs, potentially leading to a denial of service.
Certain unusual patterns of input data can cause the common function used to parse HTTP and MIME headers to allocate substantially more memory than required to hold the parsed headers. An attacker can exploit this behavior to cause an HTTP server to allocate large amounts of memory from a small request, potentially leading to memory exhaustion and a denial of service.
With fix, header parsing now correctly allocates only the memory required to hold parsed headers.
Affected range | <1.19.6 |
Fixed version | 1.19.6 |
Description
A denial of service is possible from excessive resource consumption in net/http and mime/multipart.
Multipart form parsing with mime/multipart.Reader.ReadForm can consume largely unlimited amounts of memory and disk files. This also affects form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue.
ReadForm takes a maxMemory parameter, and is documented as storing "up to maxMemory bytes +10MB (reserved for non-file parts) in memory". File parts which cannot be stored in memory are stored on disk in temporary files. The unconfigurable 10MB reserved for non-file parts is excessively large and can potentially open a denial of service vector on its own. However, ReadForm did not properly account for all memory consumed by a parsed form, such as map entry overhead, part names, and MIME headers, permitting a maliciously crafted form to consume well over 10MB. In addition, ReadForm contained no limit on the number of disk files created, permitting a relatively small request body to create a large number of disk temporary files.
With fix, ReadForm now properly accounts for various forms of memory overhead, and should now stay within its documented limit of 10MB + maxMemory bytes of memory consumption. Users should still be aware that this limit is high and may still be hazardous.
In addition, ReadForm now creates at most one on-disk temporary file, combining multiple form parts into a single temporary file. The mime/multipart.File interface type's documentation states, "If stored on disk, the File's underlying concrete type will be an *os.File.". This is no longer the case when a form contains more than one file part, due to this coalescing of parts into a single file. The previous behavior of using distinct files for each form part may be reenabled with the environment variable GODEBUG=multipartfiles=distinct.
Users should be aware that multipart.ReadForm and the http.Request methods that call it do not limit the amount of disk consumed by temporary files. Callers can limit the size of form data with http.MaxBytesReader.
Affected range | <1.19.6 |
Fixed version | 1.19.6 |
Description
Large handshake records may cause panics in crypto/tls.
Both clients and servers may send large TLS handshake records which cause servers and clients, respectively, to panic when attempting to construct responses.
This affects all TLS 1.3 clients, TLS 1.2 clients which explicitly enable session resumption (by setting Config.ClientSessionCache to a non-nil value), and TLS 1.3 servers which request client certificates (by setting Config.ClientAuth >= RequestClientCert).
Affected range | <1.19.6 |
Fixed version | 1.19.6 |
Description
A maliciously crafted HTTP/2 stream could cause excessive CPU consumption in the HPACK decoder, sufficient to cause a denial of service from a small number of small requests.
Affected range | <1.19.6 |
Fixed version | 1.19.6 |
Description
A path traversal vulnerability exists in filepath.Clean on Windows.
On Windows, the filepath.Clean function could transform an invalid path such as "a/../c:/b" into the valid path "c:\b". This transformation of a relative (if invalid) path into an absolute path could enable a directory traversal attack.
After fix, the filepath.Clean function transforms this path into the relative (but still invalid) path ".\c:\b".
Affected range | <1.18.9 |
Fixed version | 1.18.9 |
Description
On Windows, restricted files can be accessed via os.DirFS and http.Dir.
The os.DirFS function and http.Dir type provide access to a tree of files rooted at a given directory. These functions permit access to Windows device files under that root. For example, os.DirFS("C:/tmp").Open("COM1") opens the COM1 device. Both os.DirFS and http.Dir only provide read-only filesystem access.
In addition, on Windows, an os.DirFS for the directory (the root of the current drive) can permit a maliciously crafted path to escape from the drive and access any path on the system.
With fix applied, the behavior of os.DirFS("") has changed. Previously, an empty root was treated equivalently to "/", so os.DirFS("").Open("tmp") would open the path "/tmp". This now returns an error.
Affected range | <1.18.8 |
Fixed version | 1.18.8 |
Description
Due to unsanitized NUL values, attackers may be able to maliciously set environment variables on Windows.
In syscall.StartProcess and os/exec.Cmd, invalid environment variable values containing NUL values are not properly checked for. A malicious environment variable value can exploit this behavior to set a value for a different environment variable. For example, the environment variable string "A=B\x00C=D" sets the variables "A=B" and "C=D".
Affected range | <1.18.7 |
Fixed version | 1.18.7 |
Description
Programs which compile regular expressions from untrusted sources may be vulnerable to memory exhaustion or denial of service.
The parsed regexp representation is linear in the size of the input, but in some cases the constant factor can be as high as 40,000, making relatively small regexps consume much larger amounts of memory.
After fix, each regexp being parsed is limited to a 256 MB memory footprint. Regular expressions whose representation would use more space than that are rejected. Normal use of regular expressions is unaffected.
Affected range | <1.17.13 |
Fixed version | 1.17.13 |
Description
Decoding big.Float and big.Rat types can panic if the encoded message is too short, potentially allowing a denial of service.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Calling Decoder.Decode on a message which contains deeply nested structures can cause a panic due to stack exhaustion.
Affected range | <1.17.11 |
Fixed version | 1.17.11 |
Description
On Windows, rand.Read will hang indefinitely if passed a buffer larger than 1 << 32 - 1 bytes.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Unmarshaling an XML document into a Go struct which has a nested field that uses the 'any' field tag can panic due to stack exhaustion.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Calling Glob on a path which contains a large number of path separators can cause a panic due to stack exhaustion.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Calling Reader.Read on an archive containing a large number of concatenated 0-length compressed files can cause a panic due to stack exhaustion.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Calling Glob on a path which contains a large number of path separators can cause a panic due to stack exhaustion.
Affected range | <1.17.11 |
Fixed version | 1.17.11 |
Description
On Windows, the filepath.Clean function can convert certain invalid paths to valid, absolute paths, potentially allowing a directory traversal attack.
For example, Clean(".\c:") returns "c:".
Affected range | <1.18.7 |
Fixed version | 1.18.7 |
Description
Requests forwarded by ReverseProxy include the raw query parameters from the inbound request, including unparsable parameters rejected by net/http. This could permit query parameter smuggling when a Go proxy forwards a parameter with an unparsable value.
After fix, ReverseProxy sanitizes the query parameters in the forwarded query when the outbound request's Form field is set after the ReverseProxy. Director function returns, indicating that the proxy has parsed the query parameters. Proxies which do not parse query parameters continue to forward the original query parameters unchanged.
Affected range | <1.18.7 |
Fixed version | 1.18.7 |
Description
Reader.Read does not set a limit on the maximum size of file headers. A maliciously crafted archive could cause Read to allocate unbounded amounts of memory, potentially causing resource exhaustion or panics. After fix, Reader.Read limits the maximum size of header blocks to 1 MiB.
Affected range | <1.17.9 |
Fixed version | 1.17.9 |
Description
A crafted scalar input longer than 32 bytes can cause P256().ScalarMult or P256().ScalarBaseMult to panic. Indirect uses through crypto/ecdsa and crypto/tls are unaffected. amd64, arm64, ppc64le, and s390x are unaffected.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Calling Decoder.Skip when parsing a deeply nested XML document can cause a panic due to stack exhaustion.
Affected range | <1.18.6 |
Fixed version | 1.18.6 |
Description
HTTP/2 server connections can hang forever waiting for a clean shutdown that was preempted by a fatal error. This condition can be exploited by a malicious client to cause a denial of service.
Affected range | >=1.17.0-0 |
Fixed version | 1.17.8 |
Description
On 64-bit platforms, an extremely deeply nested expression can cause regexp.Compile to cause goroutine stack exhaustion, forcing the program to exit. Note this applies to very large expressions, on the order of 2MB.
Affected range | <1.17.9 |
Fixed version | 1.17.9 |
Description
encoding/pem in Go before 1.17.9 and 1.18.x before 1.18.1 has a Decode stack overflow via a large amount of PEM data.
Affected range | >=1.17.0-0 |
Fixed version | 1.17.7 |
Description
Rat.SetString had an overflow issue that can lead to uncontrolled memory consumption.
Affected range | <1.19.9 |
Fixed version | 1.19.9 |
Description
Templates containing actions in unquoted HTML attributes (e.g. "attr={{.}}") executed with empty input can result in output with unexpected results when parsed due to HTML normalization rules. This may allow injection of arbitrary attributes into tags.
Affected range | <1.19.9 |
Fixed version | 1.19.9 |
Description
Angle brackets (<>) are not considered dangerous characters when inserted into CSS contexts. Templates containing multiple actions separated by a '/' character can result in unexpectedly closing the CSS context and allowing for injection of unexpected HTML, if executed with untrusted input.
Affected range | <1.19.11 |
Fixed version | 1.19.11 |
Description
The HTTP/1 client does not fully validate the contents of the Host header. A maliciously crafted Host header can inject additional headers or entire requests.
With fix, the HTTP/1 client now refuses to send requests containing an invalid Request.Host or Request.URL.Host value.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Client IP adresses may be unintentionally exposed via X-Forwarded-For headers.
When httputil.ReverseProxy.ServeHTTP is called with a Request.Header map containing a nil value for the X-Forwarded-For header, ReverseProxy sets the client IP as the value of the X-Forwarded-For header, contrary to its documentation.
In the more usual case where a Director function sets the X-Forwarded-For header value to nil, ReverseProxy leaves the header unmodified as expected.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
The HTTP/1 client accepted some invalid Transfer-Encoding headers as indicating a "chunked" encoding. This could potentially allow for request smuggling, but only if combined with an intermediate server that also improperly failed to reject the header as invalid.
Affected range | <1.20.8 |
Fixed version | 1.20.8 |
Description
The html/template package does not apply the proper rules for handling occurrences of "<script", "<!--", and "</script" within JS literals in <script> contexts. This may cause the template parser to improperly consider script contexts to be terminated early, causing actions to be improperly escaped. This could be leveraged to perform an XSS attack.
Affected range | <1.20.8 |
Fixed version | 1.20.8 |
Description
The html/template package does not properly handle HTML-like "" comment tokens, nor hashbang "#!" comment tokens, in <script> contexts. This may cause the template parser to improperly interpret the contents of <script> contexts, causing actions to be improperly escaped. This may be leveraged to perform an XSS attack.
Affected range | <1.17.12 |
Fixed version | 1.17.12 |
Description
Calling any of the Parse functions on Go source code which contains deeply nested types or declarations can cause a panic due to stack exhaustion.
Affected range | <1.20.11 |
Fixed version | 1.20.11 |
Description
On Windows, The IsLocal function does not correctly detect reserved device names in some cases.
Reserved names followed by spaces, such as "COM1 ", and reserved names "COM" and "LPT" followed by superscript 1, 2, or 3, are incorrectly reported as local.
With fix, IsLocal now correctly reports these names as non-local.
Affected range | <1.20.12 |
Fixed version | 1.20.12 |
Description
A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body.
A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request.
Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.
Affected range | <1.19.12 |
Fixed version | 1.19.12 |
Description
Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures.
With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits.
Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.
Affected range | <1.19.7 |
Fixed version | 1.19.7 |
Description
The ScalarMult and ScalarBaseMult methods of the P256 Curve may return an incorrect result if called with some specific unreduced scalars (a scalar larger than the order of the curve).
This does not impact usages of crypto/ecdsa or crypto/ecdh.
Affected range | <1.18.9 |
Fixed version | 1.18.9 |
Description
An attacker can cause excessive memory growth in a Go server accepting HTTP/2 requests.
HTTP/2 server connections contain a cache of HTTP header keys sent by the client. While the total number of entries in this cache is capped, an attacker sending very large keys can cause the server to allocate approximately 64 MiB per open connection.
Affected range | <1.17.10 |
Fixed version | 1.17.10 |
Description
When called with a non-zero flags parameter, the Faccessat function can incorrectly report that a file is accessible.
Affected range | <1.17.11 |
Fixed version | 1.17.11 |
Description
An attacker can correlate a resumed TLS session with a previous connection.
Session tickets generated by crypto/tls do not contain a randomly generated ticket_age_add, which allows an attacker that can observe TLS handshakes to correlate successive connections by comparing ticket ages during session resumption.
github.com/docker/docker 20.10.12+incompatible
(golang)
pkg:golang/github.com/docker/[email protected]+incompatible
Unprotected Alternate Channel
Affected range | >=1.12.0 |
Fixed version | 20.10.24 |
CVSS Score | 7.5 |
CVSS Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:L |
Description
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (
dockerd
), which is developed as moby/moby is commonly referred to as Docker.Swarm Mode, which is compiled in and delivered by default in
dockerd
and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code.The
overlay
network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes.Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption.
When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the
u32
iptables extension provided by thext_u32
kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN.Two iptables rules serve to filter incoming VXLAN datagrams with a VNI that corresponds to an encrypted network and discards unencrypted datagrams. The rules are appended to the end of the
INPUT
filter chain, following any rules that have been previously set by the system administrator. Administrator-set rules take precedence over the rules Moby sets to discard unencrypted VXLAN datagrams, which can potentially admit unencrypted datagrams that should have been discarded.On Red Hat Enterprise Linux and derivatives such as CentOS and Rocky, the
xt_u32
module has been:
- moved to the kernel-modules-extra package and no longer installed by default in RHEL 8.3
- officially deprecated in RHEL 8.6
- removed completely in RHEL 9
These rules are not created when
xt_u32
is unavailable, even though the container is still attached to the network.Impact
Encrypted overlay networks on affected configurations silently accept cleartext VXLAN datagrams that are tagged with the VNI of an encrypted overlay network. As a result, it is possible to inject arbitrary Ethernet frames into the encrypted overlay network by encapsulating them in VXLAN datagrams.
The injection of arbitrary Ethernet frames can enable a Denial of Service attack. A sophisticated attacker may be able to establish a UDP or TCP connection by way of the container’s outbound gateway that would otherwise be blocked by a stateful firewall, or carry out other escalations beyond simple injection by smuggling packets into the overlay network.
Patches
Patches are available in Moby releases 23.0.3, and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16.
Workarounds
- Close the VXLAN port (by default, UDP port 4789) to incoming traffic at the Internet boundary (see GHSA-vwm3-crmr-xfxw) to prevent all VXLAN packet injection.
- Ensure that the
xt_u32
kernel module is available on all nodes of the Swarm cluster.Background
- #43382 partially discussed this concern, but did not consider the security implications.
- Mirantis FIELD-5788 essentially duplicates #43382, and was created six months earlier; it similarly overlooked the security implications.
- #45118 is the ancestor of the final patches, and was where the security implications were discovered.
Related
- CVE-2023-28841: Encrypted overlay network traffic may be unencrypted
- CVE-2023-28842: Encrypted overlay network with a single endpoint is unauthenticated
- GHSA-vwm3-crmr-xfxw: The Swarm VXLAN port may be exposed to attack due to ambiguous documentation
- GHSA-gvm4-2qqg-m333: Security issues in encrypted overlay networks (libnetwork)
Affected range | >=1.12.0 |
Fixed version | 20.10.24 |
CVSS Score | 6.8 |
CVSS Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N |
Description
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (
dockerd
), which is developed as moby/moby is commonly referred to as Docker.Swarm Mode, which is compiled in and delivered by default in
dockerd
and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code.The
overlay
network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes.Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption.
When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the
u32
iptables extension provided by thext_u32
kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN.The
overlay
driver dynamically and lazily defines the kernel configuration for the VXLAN network on each node as containers are attached and detached. Routes and encryption parameters are only defined for destination nodes that participate in the network. The iptables rules that prevent encrypted overlay networks from accepting unencrypted packets are not created until a peer is available with which to communicate.Impact
Encrypted overlay networks silently accept cleartext VXLAN datagrams that are tagged with the VNI of an encrypted overlay network. As a result, it is possible to inject arbitrary Ethernet frames into the encrypted overlay network by encapsulating them in VXLAN datagrams. The implications of this can be quite dire, and GHSA-vwm3-crmr-xfxw should be referenced for a deeper exploration.
Patches
Patches are available in Moby releases 23.0.3, and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16.
Workarounds
- In multi-node clusters, deploy a global ‘pause’ container for each encrypted overlay network, on every node. For example, use the
registry.k8s.io/pause
image and a--mode global
service.- For a single-node cluster, do not use overlay networks of any sort. Bridge networks provide the same connectivity on a single node and have no multi-node features.
The Swarm ingress feature is implemented using an overlay network, but can be disabled by publishing ports inhost
mode instead ofingress
mode (allowing the use of an external load balancer), and removing theingress
network.- If encrypted overlay networks are in exclusive use, block UDP port 4789 from traffic that has not been validated by IPSec. For example,
iptables -A INPUT -m udp —-dport 4789 -m policy --dir in --pol none -j DROP
.Background
- This issue was discovered while characterizing and mitigating CVE-2023-28840 and CVE-2023-28841.
Related
- CVE-2023-28841: Encrypted overlay network traffic may be unencrypted
- CVE-2023-28840: Encrypted overlay network may be unauthenticated
- GHSA-vwm3-crmr-xfxw: The Swarm VXLAN port may be exposed to attack due to ambiguous documentation
- GHSA-gvm4-2qqg-m333: Security issues in encrypted overlay networks (libnetwork)
Missing Encryption of Sensitive Data
Affected range | >=1.12.0 |
Fixed version | 20.10.24 |
CVSS Score | 6.8 |
CVSS Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N |
Description
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (
dockerd
), which is developed as moby/moby is commonly referred to as Docker.Swarm Mode, which is compiled in and delivered by default in
dockerd
and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code.The
overlay
network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes.Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption.
When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the
u32
iptables extension provided by thext_u32
kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN.An iptables rule designates outgoing VXLAN datagrams with a VNI that corresponds to an encrypted overlay network for IPsec encapsulation.
On Red Hat Enterprise Linux and derivatives such as CentOS and Rocky, the
xt_u32
module has been:
- moved to the kernel-modules-extra package and no longer installed by default in RHEL 8.3
- officially deprecated in RHEL 8.6
- removed completely in RHEL 9
This rule is not created when
xt_u32
is unavailable, even though the container is still attached to the network.Impact
Encrypted overlay networks on affected platforms silently transmit unencrypted data. As a result,
overlay
networks may appear to be functional, passing traffic as expected, but without any of the expected confidentiality or data integrity guarantees.It is possible for an attacker sitting in a trusted position on the network to read all of the application traffic that is moving across the overlay network, resulting in unexpected secrets or user data disclosure. Thus, because many database protocols, internal APIs, etc. are not protected by a second layer of encryption, a user may rely on Swarm encrypted overlay networks to provide confidentiality, which due to this vulnerability is no longer guaranteed.
Patches
Patches are available in Moby releases 23.0.3, and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16.
Workarounds
- Close the VXLAN port (by default, UDP port 4789) to outgoing traffic at the Internet boundary (see GHSA-vwm3-crmr-xfxw) in order to prevent unintentionally leaking unencrypted traffic over the Internet.
- Ensure that the
xt_u32
kernel module is available on all nodes of the Swarm cluster.Background
- #43382 partially discussed this concern, but did not consider the security implications.
- Mirantis FIELD-5788 essentially duplicates #43382, and was created six months earlier; it similarly overlooked the security implications.
- #45118 is the ancestor of the final patches, and was where the security implications were discovered.
Related
- CVE-2023-28840: Encrypted overlay network may be unauthenticated
- CVE-2023-28842: Encrypted overlay network with a single endpoint is unauthenticated
- GHSA-vwm3-crmr-xfxw: The Swarm VXLAN port may be exposed to attack due to ambiguous documentation
- GHSA-gvm4-2qqg-m333: Security issues in encrypted overlay networks (libnetwork)
Affected range | <24.0.7 |
Fixed version | 24.0.7 |
Description
Intel's RAPL (Running Average Power Limit) feature, introduced by the Sandy Bridge microarchitecture, provides software insights into hardware energy consumption. To facilitate this, Intel introduced the powercap framework in Linux kernel 3.13, which reads values via relevant MSRs (model specific registers) and provides unprivileged userspace access via
sysfs
. As RAPL is an interface to access a hardware feature, it is only available when running on bare metal with the module compiled into the kernel.By 2019, it was realized that in some cases unprivileged access to RAPL readings could be exploited as a power-based side-channel against security features including AES-NI (potentially inside a SGX enclave) and KASLR (kernel address space layout randomization). Also known as the PLATYPUS attack, Intel assigned CVE-2020-8694 and CVE-2020-8695, and AMD assigned CVE-2020-12912.
Several mitigations were applied; Intel reduced the sampling resolution via a microcode update, and the Linux kernel prevents access by non-root users since 5.10. However, this kernel-based mitigation does not apply to many container-based scenarios:
- Unless using user namespaces, root inside a container has the same level of privilege as root outside the container, but with a slightly more narrow view of the system
sysfs
is mounted inside containers read-only; however only read access is needed to carry out this attack on an unpatched CPUWhile this is not a direct vulnerability in container runtimes, defense in depth and safe defaults are valuable and preferred, especially as this poses a risk to multi-tenant container environments running directly on affected hardware. This is provided by masking
/sys/devices/virtual/powercap
in the default mount configuration, and adding an additional set of rules to deny it in the default AppArmor profile.While
sysfs
is not the only way to read from the RAPL subsystem, other ways of accessing it require additional capabilities such asCAP_SYS_RAWIO
which is not available to containers by default, orperf
paranoia level less than 1, which is a non-default kernel tunable.References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8694
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8695
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12912
- https://platypusattack.com/
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=949dd0104c496fa7c14991a23c03c62e44637e71
- https://web.eece.maine.edu/~vweaver/projects/rapl/
OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Affected range | <24.0.7 |
Fixed version | v24.0.7 |
Description
Intel's RAPL (Running Average Power Limit) feature, introduced by the Sandy Bridge microarchitecture, provides software insights into hardware energy consumption. To facilitate this, Intel introduced the powercap framework in Linux kernel 3.13, which reads values via relevant MSRs (model specific registers) and provides unprivileged userspace access via
sysfs
.
golang.org/x/sys 0.0.0-20211216021012-1d35b9e2eb4e
(golang)
pkg:golang/golang.org/x/[email protected]
Improper Privilege Management
Affected range | <0.0.0-20220412211240-33da011f77ad |
Fixed version | 0.0.0-20220412211240-33da011f77ad |
CVSS Score | 5.3 |
CVSS Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Description
Go before 1.17.10 and 1.18.x before 1.18.2 has Incorrect Privilege Reporting in syscall. When called with a non-zero flags parameter, the Faccessat function could incorrectly report that a file is accessible.
Specific Go Packages Affected
golang.org/x/sys/unix
github.com/opencontainers/image-spec 1.0.2-0.20211117181255-693428a734f5
(golang)
pkg:golang/github.com/opencontainers/[email protected]
Access of Resource Using Incompatible Type ('Type Confusion')
Affected range | <1.0.2 |
Fixed version | 1.0.2 |
CVSS Score | 3 |
CVSS Vector | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N |
Description
Impact
In the OCI Image Specification version 1.0.1 and prior, manifest and index documents are not self-describing and documents with a single digest could be interpreted as either a manifest or an index.
Patches
The Image Specification will be updated to recommend that both manifest and index documents contain a
mediaType
field to identify the type of document.
Release v1.0.2 includes these updates.Workarounds
Software attempting to deserialize an ambiguous document may reject the document if it contains both “manifests” and “layers” fields or “manifests” and “config” fields.
References
For more information
If you have any questions or comments about this advisory:
OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Affected range | <1.0.2 |
Fixed version | 1.0.2 |
Description
Impact
In the OCI Image Specification version 1.0.1 and prior, manifest and index documents are not self-describing and documents with a single digest could be interpreted as either a manifest or an index.
Patches
The Image Specification will be updated to recommend that both manifest and index documents contain a
mediaType
field to identify the type of document.
No description provided.