GHSA-JQ35-85CJ-FJ4P

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

• 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/

Kodem intelligence

1. What is GHSA-JQ35-85CJ-FJ4P? GHSA-JQ35-85CJ-FJ4P is a medium-severity security vulnerability in github.com/docker/docker (go), affecting versions >= 24.0.0, < 24.0.7. It is fixed in 24.0.7, 23.0.8, 20.10.27.
2. Which versions of github.com/docker/docker are affected by GHSA-JQ35-85CJ-FJ4P? github.com/docker/docker (go) versions >= 24.0.0, < 24.0.7 is affected.
3. Is there a fix for GHSA-JQ35-85CJ-FJ4P? Yes. GHSA-JQ35-85CJ-FJ4P is fixed in 24.0.7, 23.0.8, 20.10.27. Upgrade to this version or later.
4. Is GHSA-JQ35-85CJ-FJ4P exploitable, and should I be worried? Whether GHSA-JQ35-85CJ-FJ4P is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether GHSA-JQ35-85CJ-FJ4P is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix GHSA-JQ35-85CJ-FJ4P?
   • Upgrade github.com/docker/docker to 24.0.7 or later
   • Upgrade github.com/docker/docker to 23.0.8 or later
   • Upgrade github.com/docker/docker to 20.10.27 or later