What’s Vulnerable › Vulnerabilities
CVE-2024-21626: runc container breakout through process.cwd trickery and leaked fds
- Severity: high (CVSS 8.6 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 18.9% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2024-01-31 · updated 2026-09-17
- Weakness: CWE-403
Description
runc is a CLI tool for spawning and running containers on Linux according to the OCI specification. In runc 1.1.11 and earlier, due to an internal file descriptor leak, an attacker could cause a newly-spawned container process (from runc exec) to have a working directory in the host filesystem namespace, allowing for a container escape by giving access to the host filesystem ("attack 2"). The same attack could be used by a malicious image to allow a container process to gain access to the host filesystem through runc run ("attack 1"). Variants of attacks 1 and 2 could be also be used to overwrite semi-arbitrary host binaries, allowing for complete container escapes ("attack 3a" and "attack 3b"). runc 1.1.12 includes patches for this issue.
Affected products
- Fedoraproject Fedora: 39
- opencontainers runc: before 1.1.12 — fixed in 1.1.12
How to fix
Upgrade to a fixed version: opencontainers runc 1.1.12. Check the vendor advisory for mitigations.
References
- http://packetstormsecurity.com/files/176993/runc-1.1.11-File-Descriptor-Leak-Privilege-Escalation.html
- http://www.openwall.com/lists/oss-security/2024/02/01/1
- http://www.openwall.com/lists/oss-security/2024/02/02/3
- https://github.com/opencontainers/runc/commit/02120488a4c0fc487d1ed2867e901eeed7ce8ecf
- https://github.com/opencontainers/runc/releases/tag/v1.1.12
- https://github.com/opencontainers/runc/security/advisories/GHSA-xr7r-f8xq-vfvv
- https://lists.debian.org/debian-lts-announce/2024/02/msg00005.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2NLXNE23Q5ESQUAI22Z7A63JX2WMPJ2J/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SYMO3BANINS6RGFQFKPRG4FIOJ7GWYTL/
- http://packetstormsecurity.com/files/176993/runc-1.1.11-File-Descriptor-Leak-Privilege-Escalation.html
- http://www.openwall.com/lists/oss-security/2024/02/01/1
- http://www.openwall.com/lists/oss-security/2024/02/02/3
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