TCP spoofing vulnerability in pf(4)

Description

In versions of FreeBSD 14.0-RELEASE before 14-RELEASE-p2, FreeBSD 13.2-RELEASE before 13.2-RELEASE-p7 and FreeBSD 12.4-RELEASE before 12.4-RELEASE-p9, the pf(4) packet filter incorrectly validates TCP sequence numbers.  This could allow a malicious actor to execute a denial-of-service attack against hosts behind the firewall.

Scores

EPSS (exploitation in 30 days)

0.74% · top 45% of all CVEs (6 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.

Affected products

• FreeBSD · FreeBSD

  • affected 14.0-RELEASE – < p2
  • affected 13.2-RELEASE – < p7
  • affected 12.4-RELEASE – < p9

References (2)

• https://security.freebsd.org/advisories/FreeBSD-SA-23:17.pf.asc (opens in a new tab)vendor-advisoryx_transferred
• https://security.netapp.com/advisory/ntap-20240112-0007/ (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2023-6534](https://trackcve.app/badge/CVE-2023-6534.svg)](https://trackcve.app/cve/CVE-2023-6534)

Record last updated 13 Feb 2025, 17:26 UTC.