Vulnerability in FreeBSD

CVE-2024-6640

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.005 (37.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2024-6640: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

  • FreeBSD — versions 14.1-RELEASE, 14.0-RELEASE, 13.3-RELEASE

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-6640?
CVE-2024-6640 is a medium-severity vulnerability in FreeBSD, classified under Incorrect Default Permissions. CVSS score: 6.3/10. Published 2024-08-12.
How severe is CVE-2024-6640?
Medium severity. CVSS v3 base score is 6.3 out of 10.