CVE-2024-43806

rustix's rustix::fs::Dir iterator with the linux_raw backend can cause memory explosion

If a program tries to access a directory with its file descriptor after the file has been unlinked (or any other action that leaves the Dir iterator in the stuck state), and the implementation does not break after seeing an error, it can cause a memory explosion.

As an example, Linux's various virtual file systems (e.g. /proc, /sys) can contain directories that spontaneously pop in and out of existence. Attempting to iterate over them using rustix::fs::Dir directly or indirectly (e.g. with the procfs crate) can trigger this fault condition if the implementation decides to continue on errors.

An attacker knowledgeable about the implementation details of a vulnerable target can therefore try to trigger this fault condition via any one or a combination of several available APIs. If successful, the application host will quickly run out of memory, after which the application will likely be terminated by an OOM killer, leading to denial of service.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2024-43806 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.35.15, 0.36.16, 0.37.25, 0.38.19); upgrading removes the vulnerable code path.

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1. What is CVE-2024-43806? CVE-2024-43806 is a medium-severity uncontrolled resource consumption vulnerability in rustix (rust), affecting versions >= 0.35.11, < 0.35.15. It is fixed in 0.35.15, 0.36.16, 0.37.25, 0.38.19. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2024-43806? CVE-2024-43806 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of rustix are affected by CVE-2024-43806? rustix (rust) versions >= 0.35.11, < 0.35.15 is affected.
4. Is there a fix for CVE-2024-43806? Yes. CVE-2024-43806 is fixed in 0.35.15, 0.36.16, 0.37.25, 0.38.19. Upgrade to this version or later.
5. Is CVE-2024-43806 exploitable, and should I be worried? Whether CVE-2024-43806 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
6. What actually determines whether CVE-2024-43806 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.
7. How do I fix CVE-2024-43806?
   • Upgrade rustix to 0.35.15 or later
   • Upgrade rustix to 0.36.16 or later
   • Upgrade rustix to 0.37.25 or later
   • Upgrade rustix to 0.38.19 or later