What’s Vulnerable › Vulnerabilities

CVE-2020-24863

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-09-03 · updated 2026-06-17
• Weakness: CWE-787

Description

A memory corruption vulnerability was found in the kernel function kern_getfsstat in MidnightBSD before 1.2.7 and 1.3 through 2020-08-19, and FreeBSD through 11.4, that allows an attacker to trigger an invalid free and crash the system via a crafted size value in conjunction with an invalid mode.

Affected products

• FreeBSD: through 11.4
• Midnightbsd: before 1.2.7; from 1.3 through 2020-08-19 — fixed in 1.2.7

How to fix

Upgrade to a fixed version: Midnightbsd 1.2.7. Check the vendor advisory for mitigations.

References

• http://www.midnightbsd.org/security/adv/MIDNIGHTBSD-SA-20:01.txt
• https://github.com/MidnightBSD/src/blob/1691c07ff4f27b97220a5d65e217341e477f4014/sys/kern/vfs_syscalls.c
• https://www.freebsd.org/security/advisories/FreeBSD-EN-20:18.getfsstat.asc
• https://www.midnightbsd.org/notes/
• http://www.midnightbsd.org/security/adv/MIDNIGHTBSD-SA-20:01.txt
• https://github.com/MidnightBSD/src/blob/1691c07ff4f27b97220a5d65e217341e477f4014/sys/kern/vfs_syscalls.c
• https://www.freebsd.org/security/advisories/FreeBSD-EN-20:18.getfsstat.asc
• https://www.midnightbsd.org/notes/

Get alerted when CVE-2020-24863 or the next vulnerability affects your stack