Skip to content
Log inStart free trial

GHSA-jq35-85cj-fj4p

/sys/devices/virtual/powercap accessible by default to containers

Medium Go
Severity
Medium
The publisher's own rating, not a CVSS score
Exploit chance (EPSS)
—
No score published
Known exploited
No
Not in CISA's catalog
Weakness
—
Not classified
Fix
24.0.7
Upgrade github.com/docker/docker to this version or later

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 CPU

While 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 as CAP_SYS_RAWIO which is not available to containers by default, or perf paranoia level less than 1, which is a non-default kernel tunable.

References

Affected versions

Go

PackageVulnerableFixed in
github.com/docker/docker
>= 24.0.0, < 24.0.7
24.0.7
github.com/docker/docker
>= 21.0.0, < 23.0.8
23.0.8
github.com/docker/docker
< 20.10.27
20.10.27

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/docker/docker Go → 24.0.7

go
go get github.com/docker/docker@v24.0.7 && go mod tidy

References

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
AdvisorySeverityWhy it's related
GHSA-rg2x-37c3-w2rh
Docker: Race condition in docker cp allows bind mount redirection to host path
High Also affects github.com/docker/docker
GHSA-vp62-88p7-qqf5
Docker: Race condition in docker cp allows creation of arbitrary empty files on the host via symlink swap
Medium Also affects github.com/docker/docker
GHSA-x86f-5xw2-fm2r
Docker: `PUT /containers/{id}/archive` executes container binary on the host
High Also affects github.com/docker/docker
GO-2026-4887
Moby has AuthZ plugin bypass when provided oversized request bodies
High Also affects github.com/docker/docker
GHSA-pxq6-2prw-chj9
Moby has an Off-by-one error in its plugin privilege validation
High Also affects github.com/docker/docker
GHSA-4vq8-7jfc-9cvp
Moby firewalld reload removes bridge network isolation
Medium Also affects github.com/docker/docker
GHSA-x4rx-4gw3-53p4
Moby firewalld reload makes published container ports accessible from remote hosts
Medium Also affects github.com/docker/docker
GHSA-v23v-6jw2-98fq
Authz zero length regression
Critical Also affects github.com/docker/docker
Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor