CVE-2020-25577: Freebsd

Critical severity, CVSS 9.8. EPSS: 1.5% chance of exploitation in the next 30 days.

In FreeBSD 12.2-STABLE before r368250, 11.4-STABLE before r368253, 12.2-RELEASE before p1, 12.1-RELEASE before p11 and 11.4-RELEASE before p5 rtsold(8) does not verify that the RDNSS option does not extend past the end of the received packet before processing its contents. While the kernel currently ignores such malformed packets, it passes them to userspace programs. Any programs expecting the kernel to do validation may be vulnerable to an overflow.

Affected products

• Freebsd Freebsd: version 11.4 only; version 12.1 only; version 12.2 only

Published 2021-03-29. Last modified 2026-06-17.