CVE-2016-1886

HIGH

FreeBSD <9.3 p42, 10.1 p34, 10.2 p17, 10.3 p3 - Memory Corruption via SETFKEY ioctl

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2016-1886. PoCs published by CTurt.

AI-analyzed exploit summary This exploit leverages a heap overflow in the FreeBSD kernel's function key handling (CVE-2016-1886) to overwrite stack memory and redirect execution to a kernel payload, achieving local privilege escalation.

Description

Integer signedness error in the genkbd_commonioctl function in sys/dev/kbd/kbd.c in FreeBSD 9.3 before p42, 10.1 before p34, 10.2 before p17, and 10.3 before p3 allows local users to obtain sensitive information from kernel memory, cause a denial of service (memory overwrite and kernel crash), or gain privileges via a negative value in the flen structure member in the arg argument in a SETFKEY ioctl call, which triggers a "two way heap and stack overflow."

Exploits (1)

exploitdb WORKING POC
by CTurt · cdosfreebsd_x86-64
https://www.exploit-db.com/exploits/44211

This exploit leverages a heap overflow in the FreeBSD kernel's function key handling (CVE-2016-1886) to overwrite stack memory and redirect execution to a kernel payload, achieving local privilege escalation.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: FreeBSD kernel (versions prior to fix for CVE-2016-1886)
No auth needed
Prerequisites: Local access to a vulnerable FreeBSD system · Kernel symbols resolution via kldsym
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (5)

Core 5
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1035905
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/90734
Vendor Advisory vendor-advisory x_refsource_freebsd
https://www.freebsd.org/security/advisories/FreeBSD-SA-16:18.atkbd.asc
Exploit x_refsource_misc
http://cturt.github.io/SETFKEY.html

Scores

CVSS v3 7.8
EPSS 0.0022
EPSS Percentile 44.8%
Attack Vector LOCAL
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-119
Status published
Products (4)
freebsd/freebsd 9.3
freebsd/freebsd 10.1
freebsd/freebsd 10.2
freebsd/freebsd 10.3
Published May 25, 2016
Tracked Since Feb 18, 2026