CVE-2018-17155

Severity: medium (CVSS 5.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-09-28 · updated 2026-06-17
Weakness: CWE-200

Description

In FreeBSD before 11.2-STABLE(r338983), 11.2-RELEASE-p4, 11.1-RELEASE-p15, 10.4-STABLE(r338984), and 10.4-RELEASE-p13, due to insufficient initialization of memory copied to userland in the getcontext and swapcontext system calls, small amounts of kernel memory may be disclosed to userland processes. Unprivileged authenticated local users may be able to access small amounts privileged kernel data.

Affected products

FreeBSD: before 11.2; 10.4, 10.4-p13, 11.1-p15, 11.2-p4 — fixed in 11.2

How to fix

Upgrade to a fixed version: FreeBSD 11.2. Check the vendor advisory for mitigations.

References

https://security.FreeBSD.org/advisories/FreeBSD-EN-18:12.mem.asc
https://security.FreeBSD.org/advisories/FreeBSD-EN-18:12.mem.asc

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