CVE-2020-12242

HIGH

Valve Source - Local Privilege Escalation via /tmp/hl2_relaunch File Execution

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2020-12242. PoCs published by 0xEmma.

AI-analyzed exploit summary This exploit leverages CVE-2020-12242 to achieve arbitrary code execution on macOS by injecting a payload into the '/tmp/hl2_relaunch' file, which is then executed by the Source Engine. The exploit is straightforward and requires user interaction to input the command.

Description

Valve Source allows local users to gain privileges by writing to the /tmp/hl2_relaunch file, which is later executed in the context of a different user account.

Exploits (1)

exploitdb WORKING POC
by 0xEmma · textlocalmacos
https://www.exploit-db.com/exploits/48387

This exploit leverages CVE-2020-12242 to achieve arbitrary code execution on macOS by injecting a payload into the '/tmp/hl2_relaunch' file, which is then executed by the Source Engine. The exploit is straightforward and requires user interaction to input the command.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Source Engine (CS:GO BuildID: 4937372, TF2 BuildID: 4871679, Garry's Mod BuildID: 4803834, Half Life 2 BuildID: 4233302)
No auth needed
Prerequisites: macOS environment · Write access to '/tmp/hl2_relaunch' · Source Engine game execution context
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (1)

Core 1
Core References
Exploit, Third Party Advisory x_refsource_misc
https://0xem.ma/cve/2020/04/28/Source-hl2-relaunch-exec.html

Scores

CVSS v3 7.8
EPSS 0.0109
EPSS Percentile 61.0%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-78
Status published
Products (1)
valvesoftware/source
Published Apr 27, 2020
Tracked Since Feb 18, 2026