Skip to content
CVE Tracker
  • Newest CVEsPage
  • Recently added to KEVPage
  • Rising exploitation (EPSS)Page
  • Weekly digestPage
  • StatisticsPage
  • WatchlistPage
  • API documentationPage
  • MCP serverPage
  • Data sourcesPage
  • ChangelogPage
  • AboutPage
  • How it's builtPage
Back

CVE-2024-6640

pf incorrectly matches different ICMPv6 states in the state table

Medium6.3EPSS 0.46%
Published
Updated
Reserved
Assigned by
freebsd

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.

Scores

CVSS scores of CVE-2024-6640, by who scored it
Scored byCVSSScoreVector
CISA-ADPADP (enrichment)3.1Medium6.3CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
NVDNVD · Deferred3.1Medium6.3CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS (exploitation in 30 days)
0.46% · top 60% of all CVEs (7 Nov 2026)
CISA SSVC
Exploitation: none · Automatable: no · Technical impact: partial
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.

Weakness

Affected products

  • FreeBSD · FreeBSD

    • affected 14.1-RELEASE – < p3
    • affected 14.0-RELEASE – < p9
    • affected 13.3-RELEASE – < p5

References (2)

Sources

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

Badge for a README or a ticket

CVE-2024-6640 badge
[![CVE-2024-6640](https://trackcve.app/badge/CVE-2024-6640.svg)](https://trackcve.app/cve/CVE-2024-6640)

Record last updated .