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Fencer Vulns
high 7.8

CVE-2023-2640 in the critical feed json

On Ubuntu kernels carrying both c914c0e27eb0 and "UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs", an un…

published 2023-07-26 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-34106

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
15.2%
EPSS 15.2% chance of exploitation in 30 days, percentile 96%
public exploits
1
Metasploit

Summary

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.

Patch / fix

  • canonical ubantu_kernel 5.4.0-155.172, 6.0.0-1020.20, 6.2.0-26.26
  • linux Ubuntu 22.04 LTS 5.15.0-177.187
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1106.113
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1106.115
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1102.108
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1100.103
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1098.103
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1111.120
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1089.97

ubuntu advisories UBUNTU-CVE-2023-2640

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-2640 updated cvss 7.8

kernel: overlayfs: In Ubuntu skip permission checking for trusted.overlayfs.* xattrs

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (Metasploit exploit/linux/local/gameoverlay_privesc)
  2. Published

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 y ago

Exploit prediction

15.20% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Canonical Ubuntu Kernel
  • canonical ubantu_kernel

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.