CVE-2021-3847

An unauthorized access to the execution of the setuid file with capabilities flaw in the Linux kernel OverlayFS subsystem was found in the way user copying a capable file from a nosuid mount into another mount. A local user could use this flaw to escalate their privileges on the system.

Weakness

The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.

Affected Software

References

• https://bugzilla.redhat.com/show_bug.cgi?id=2009704
• https://www.openwall.com/lists/oss-security/2021/10/14/3
• https://bugzilla.redhat.com/show_bug.cgi?id=2009704
• https://www.openwall.com/lists/oss-security/2021/10/14/3