CVE-2024-6640 - CVE House
Back to Database
Status published Unknown CVE-2024-6640

pf incorrectly matches different ICMPv6 states in the state table

Vulnerability Description

In ICMPv6 Neighbor Discovery (ND), the ID is always 0. When pf is configured to allow ND and block incoming Echo Requests, a crafted Echo Request packet after a Neighbor Solicitation (NS) can trigger an Echo Reply. The packet has to come from the same host as the NS and have a zero as identifier to match the state created by the Neighbor Discovery and allow replies to be generated. ICMPv6 packets with identifier value of zero bypass firewall rules written on the assumption that the incoming packets are going to create a state in the state table.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2024-6640

Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Enrico Bassetti e.bassetti@tudelft.nl (Cybersecurity @ TU Delft, SPRITZ Group @ UniPD)

References

More from FreeBSD

View All →
CVE-2025-24934
SO_REUSEPORT_LB breaks connect(2) for UDP sockets
Unknown 0
CVE-2025-15576
Jail chroot escape via fd exchange with a different jail
Unknown 0
CVE-2025-15547
Jail escape by a privileged user via nullfs
Unknown 0
CVE-2025-14769
ipfw denial of service
Unknown 0
CVE-2025-14558
Remote code execution via ND6 Router Advertisements
Unknown 0

Affected Vendor

Affected Software

FreeBSD
Vulnerable Versions:
14.1-RELEASE, 14.0-RELEASE, 13.3-RELEASE

Timeline

Official Publish: August 11th, 2024
Last Modified: November 26th, 2024
Added to House: July 22nd, 2026

CVSS Vectors

No vector data available

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.