Vulnerability Details : CVE-2021-3864
Potential exploit
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.
Vulnerability category: BypassGain privilege
Products affected by CVE-2021-3864
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-3864
0.79%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 71 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-3864
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
7.0
|
HIGH | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.0
|
5.9
|
NIST |
CWE ids for CVE-2021-3864
-
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.Assigned by: secalert@redhat.com (Primary)
References for CVE-2021-3864
-
https://bugzilla.redhat.com/show_bug.cgi?id=2015046
2015046 – (CVE-2021-3864) CVE-2021-3864 kernel: descendant's dumpable setting with certain SUID binariesIssue Tracking;Patch;Third Party Advisory
-
https://lore.kernel.org/all/20211221021744.864115-1-longman%40redhat.com/
[PATCH] exec: Make suid_dumpable apply to SUID/SGID binaries irrespective of invoking users - Waiman Long
-
https://www.openwall.com/lists/oss-security/2021/10/20/2
oss-security - Core-dump handing issues with suid binariesExploit;Mailing List;Third Party Advisory
-
https://lore.kernel.org/all/20211226150310.GA992%401wt.eu/
Re: [PATCH] exec: Make suid_dumpable apply to SUID/SGID binaries irrespective of invoking users - Willy Tarreau
-
https://access.redhat.com/security/cve/CVE-2021-3864
CVE-2021-3864- Red Hat Customer PortalThird Party Advisory
-
https://security-tracker.debian.org/tracker/CVE-2021-3864
CVE-2021-3864Third Party Advisory
-
https://lore.kernel.org/lkml/20211228170910.623156-1-wander%40redhat.com/
[PATCH RFC v2 0/4] coredump: mitigate privilege escalation of process coredump - Wander Lairson Costa
Jump to