Improper Access Control The advisory has been revoked - it doesn't affect any version of package linux-qemu-6.18 (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-CHAINGUARDLATEST-LINUXQEMU618-15043885
- published21 Jan 2026
- disclosed26 Aug 2022
Introduced: 26 Aug 2022
CVE-2021-3864 (opens in a new tab)Amendment
The Chainguard security team deemed this advisory irrelevant for Chainguard:latest.
NVD Description
Note: Versions mentioned in the description apply only to the upstream linux-qemu-6.18 package and not the linux-qemu-6.18 package as distributed by Chainguard.
A flaw was found in the way the dumpable flag setting was handled when certain SUID binaries executed its descendants. The prerequisite is a SUID binary that sets real UID equal to effective UID, and real GID equal to effective GID. The descendant will then have a dumpable value set to 1. As a result, if the descendant process crashes and core_pattern is set to a relative value, its core dump is stored in the current directory with uid:gid permissions. An unprivileged local user with eligible root SUID binary could use this flaw to place core dumps into root-owned directories, potentially resulting in escalation of privileges.
References
- https://lore.kernel.org/all/20211221021744.864115-1-longman@redhat.com/
- https://lore.kernel.org/all/20211226150310.GA992@1wt.eu/
- https://lore.kernel.org/lkml/20211228170910.623156-1-wander@redhat.com/
- https://access.redhat.com/security/cve/CVE-2021-3864
- https://bugzilla.redhat.com/show_bug.cgi?id=2015046
- https://lore.kernel.org/all/20211221021744.864115-1-longman%40redhat.com/
- https://lore.kernel.org/all/20211226150310.GA992%401wt.eu/
- https://lore.kernel.org/lkml/20211228170910.623156-1-wander%40redhat.com/
- https://security-tracker.debian.org/tracker/CVE-2021-3864
- https://www.openwall.com/lists/oss-security/2021/10/20/2