Buffer overflow in Linux Linux_kernel

CVE-2021-33909

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd8…

Vulnerability class: Integer Overflow

EPSS: 0.097 (95.0th 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

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
  • cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-33909?
CVE-2021-33909 is a high-severity vulnerability in Linux Linux_kernel, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2021-07-20.
How severe is CVE-2021-33909?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2021-33909 known to be exploited?
41 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.