CVSS 3.1
7.0 highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HCVE-2021-3864
High (7.0). EPSS 0.8% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 0.8% chance of exploitation in the next 30 days; higher than 55% of CVEs (scores of 2026-10-31)
- CWE
- CWE-284
- Published
- Modified
- Record from
- the NVD, synced
Affected
- debian:debian_linux
- linux:linux_kernel
- redhat:enterprise_linux
References
- 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/