CVE-2021-3864: Debian Linux

High severity, CVSS 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.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only
• Linux Linux Kernel: affected versions not specified
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 9.0 only

Published 2022-08-26. Last modified 2026-06-17.