CVE-2020-7451

MEDIUM

FreeBSD 12.1/11.3 Uninitialized Memory Disclosure via IPv6 TCP Traffic Class

Title source: llm

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.

References (1)

Core 1

Core References

Patch, Vendor Advisory x_refsource_confirm

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

Scores

CVSS v3 5.3

EPSS 0.0033

EPSS Percentile 55.7%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Details

CWE

CWE-908

Status published

Products (2)

freebsd/freebsd 11.3 (7 CPE variants)

freebsd/freebsd 12.1 (3 CPE variants)

Published Apr 28, 2020

Tracked Since Feb 18, 2026