CVE-2020-7451

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-04-28 · updated 2026-06-17
Weakness: CWE-908

Description

In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.

Affected products

FreeBSD: 11.3, 11.3-p1, 11.3-p2, 11.3-p3, 11.3-p4, 11.3-p5 (+4)

References

https://security.FreeBSD.org/advisories/FreeBSD-SA-20:04.tcp.asc
https://security.FreeBSD.org/advisories/FreeBSD-SA-20:04.tcp.asc

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