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TI-2023-04426 Aliases CVE-2023-4809GHSA-g6hh-x63c-83gf

pf incorrectly handles multiple IPv6 fragment headers

Priority LOW 34CWE-167Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

In pf packet processing with a 'scrub fragment reassemble' rule, a packet containing multiple IPv6 fragment headers would be reassembled, and then immediately processed. That is, a packet with multiple fragment extension headers would not be recognized as the correct ultimate payload. Instead a packet with multiple IPv6 fragment headers would unexpectedly be interpreted as a fragmented packet, rather than as whatever the real payload is. As a result, IPv6 fragments may bypass pf firewall rules written on the assumption all fragments have been reassembled and, as a result, be forwarded or processed by the host.

Why it matters now

EPSS 0.00802 56th percentileScored 2026-11-07
Fix Fixed FreeBSD (FreeBSD): p3, p5

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeBSDFreeBSD13.2-RELEASE to before p3; 12.4-RELEASE to before p5p3, p5Patch availableCNA
  • FreeBSD VendorFreeBSD Affected 13.2-RELEASE to before p3; 12.4-RELEASE to before p5 Fixed in p3, p5 Patch available CNA

CPE configurations NVD · 11

CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*before 12.4; 13.0 to before 13.2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:-:*:*:*:*:*:*12.4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:p1:*:*:*:*:*:*12.4 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:p2:*:*:*:*:*:*12.4 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:p3:*:*:*:*:*:*12.4 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:p4:*:*:*:*:*:*12.4 p4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:rc2-p1:*:*:*:*:*:*12.4 rc2-p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:12.4:rc2-p2:*:*:*:*:*:*12.4 rc2-p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:13.2:-:*:*:*:*:*:*13.2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:13.2:p1:*:*:*:*:*:*13.2 p1VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:* Versions before 12.4; 13.0 to before 13.2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:-:*:*:*:*:*:* Versions 12.4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:p1:*:*:*:*:*:* Versions 12.4 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:p2:*:*:*:*:*:* Versions 12.4 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:p3:*:*:*:*:*:* Versions 12.4 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:p4:*:*:*:*:*:* Versions 12.4 p4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:rc2-p1:*:*:*:*:*:* Versions 12.4 rc2-p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:12.4:rc2-p2:*:*:*:*:*:* Versions 12.4 rc2-p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:13.2:-:*:*:*:*:*:* Versions 13.2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:13.2:p1:*:*:*:*:*:* Versions 13.2 p1 Vulnerable ·FreeBSD
Show 1 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:13.2:p2:*:*:*:*:*:*13.2 p2VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:13.2:p2:*:*:*:*:*:* Versions 13.2 p2 Vulnerable ·FreeBSD

Remediation

  • Fix · CNA FreeBSD (FreeBSD) Fixed in p3, p5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-4809
  2. 2026-10-03 Alias added: GHSA-g6hh-x63c-83gf

References

Advisory 4

Other 1

  • TI-2011-04182 Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT… CVSS 2.0HIGH 10.0
  • TI-2007-03684 Integer overflow in print-bgp.c in the BGP dissector in tcpdump 3.9.6 and earlier allows… CVSS 3.1CRITICAL 9.8
  • TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
  • TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
  • TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
  • TI-2003-00642 The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code… CVSS 2.0HIGH 10.0
See all 576 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences