CVE-2024-45310

Description

runc is a CLI tool for spawning and running containers according to the OCI specification. runc 1.1.13 and earlier, as well as 1.2.0-rc2 and earlier, can be tricked into creating empty files or directories in arbitrary locations in the host filesystem by sharing a volume between two containers and exploiting a race with `os.MkdirAll`. While this could be used to create empty files, existing files would not be truncated. An attacker must have the ability to start containers using some kind of custom volume configuration. Containers using user namespaces are still affected, but the scope of places an attacker can create inodes can be significantly reduced. Sufficiently strict LSM policies (SELinux/Apparmor) can also in principle block this attack -- we suspect the industry standard SELinux policy may restrict this attack's scope but the exact scope of protection hasn't been analysed. This is exploitable using runc directly as well as through Docker and Kubernetes. The issue is fixed in runc v1.1.14 and v1.2.0-rc3. Some workarounds are available. Using user namespaces restricts this attack fairly significantly such that the attacker can only create inodes in directories that the remapped root user/group has write access to. Unless the root user is remapped to an actual user on the host (such as with rootless containers that don't use `/etc/sub[ug]id`), this in practice means that an attacker would only be able to create inodes in world-writable directories. A strict enough SELinux or AppArmor policy could in principle also restrict the scope if a specific label is applied to the runc runtime, though neither the extent to which the standard existing policies block this attack nor what exact policies are needed to sufficiently restrict this attack have been thoroughly tested.

Reserved 2024-08-26 | Published 2024-09-03 | Updated 2024-09-03 | Assigner GitHub_M

Problem types

CWE-363: Race Condition Enabling Link Following

CWE-61: UNIX Symbolic Link (Symlink) Following

Product status

< 1.1.14
affected

>= 1.2.0-rc-1, < 1.2.0-rc.3
affected

References

github.com/...s/runc/security/advisories/GHSA-jfvp-7x6p-h2pv

github.com/opencontainers/runc/pull/4359

github.com/...ommit/63c2908164f3a1daea455bf5bcd8d363d70328c7

github.com/...ommit/8781993968fd964ac723ff5f360b6f259e809a3e

github.com/...ommit/f0b652ea61ff6750a8fcc69865d45a7abf37accf

cve.org (CVE-2024-45310)

nvd.nist.gov (CVE-2024-45310)

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