Auth bypass in Canonical Ubuntu Kernel
CVE-2023-2640
On Ubuntu kernels carrying both c914c0e27eb0 and "UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs", an unprivileged user may set privileged extended attributes on the mounted files, leading them to be set on the upper files without the appropriate security checks.
Vulnerability class: Broken Access Control
EPSS: 0.161 (96.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Canonical Ubuntu Kernel — versions 0
- Canonical Ubuntu_linux — versions 23.04
Weakness classification (CWE)
Public proof-of-concept exploits
- g1vi/CVE-2023-2640-CVE-2023-32629
- luanoliveira350/GameOverlayFS
- OllaPapito/gameoverlay
- musorblyat/CVE-2023-2640-CVE-2023-32629
- K5LK/CVE-2023-2640-32629
- Nkipohcs/CVE-2023-2640-CVE-2023-32629
- SanjayRagavendar/Ubuntu-GameOver-Lay
- WhatsWrongAndWhy/CVE-2023-2640-CVE-2023-32629
- amar-imamovic/CVE-2023-2640-CVE-2023-32629-Interactive-PoC
- z3usx01/CVE-2023-2640-3262-PoC
References
- security@ubuntu.com (vendor-advisory, Vendor Advisory)
- security@ubuntu.com (issue-tracking, Third Party Advisory)
- security@ubuntu.com (Exploit, technical-description, Third Party Advisory, Mitigation)
- security@ubuntu.com (mailing-list, Patch, Mailing List)
Frequently asked questions
- What is CVE-2023-2640?
- CVE-2023-2640 is a high-severity vulnerability in Canonical Ubuntu Kernel, classified under Incorrect Authorization. CVSS score: 7.8/10. Published 2023-07-26.
- How severe is CVE-2023-2640?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2023-2640 known to be exploited?
- 66 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.