SB2021041701 - Incorrect authorization in Linux kernel fs
Published: April 17, 2021 Updated: June 21, 2024
Security Bulletin ID
SB2021041701
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Incorrect authorization (CVE-ID: CVE-2021-3493)
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to incorrect authorization error within the validheader() and cap_convert_nscap() functions in security/commoncap.c, within the vfs_setxattr() and setxattr() functions in fs/xattr.c. A local user can execute arbitrary code.
Remediation
Install update from vendor's website.
References
- https://www.openwall.com/lists/oss-security/2021/04/16/1
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52
- https://ubuntu.com/security/notices/USN-4917-1
- http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html
- http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html
- http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html