CVE-2024-21626

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.

Weakness

The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

Affected Software

Extended Description

Resources such as files and directories may be inadvertently exposed through mechanisms such as insecure permissions, or when a program accidentally operates on the wrong object. For example, a program may intend that private files can only be provided to a specific user. This effectively defines a control sphere that is intended to prevent attackers from accessing these private files. If the file permissions are insecure, then parties other than the user will be able to access those files. A separate control sphere might effectively require that the user can only access the private files, but not any other files on the system. If the program does not ensure that the user is only requesting private files, then the user might be able to access other files on the system. In either case, the end result is that a resource has been exposed to the wrong party.

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/