CVE-2021-3864

 

Published at: - 26-08-2022 06:15

Last modified: - 01-09-2022 05:56

Total changes: - 2

Description

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.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

 

Verification logic

 

Reference

• https://bugzilla.redhat.com/show_bug.cgi?id=2015046
• https://www.openwall.com/lists/oss-security/2021/10/20/2
• https://access.redhat.com/security/cve/CVE-2021-3864
• https://security-tracker.debian.org/tracker/CVE-2021-3864
• https://lore.kernel.org/all/20211221021744.864115-1-longman@redhat.com/
• https://lore.kernel.org/lkml/20211228170910.623156-1-wander@redhat.com/
• https://lore.kernel.org/all/20211226150310.GA992@1wt.eu/

 

Keywords

NVD

 

CVE-2021-3864

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures