HOMEVULNERABILITIESCVE-2020-12242
HIGHPOC

CVE-2020-12242

CWE-78Published: April 27, 2020· Updated: Jun 17, 2026

7.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-12242 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

A proof-of-concept (PoC) exploit exists for CVE-2020-12242. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

valvesoftware1 product(s)
source
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

POC AVAILABLEProof-of-concept code exists
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://0xem.ma/cve/2020/04/28/Source-hl2-relaunch-exec.html
ADVISORYhttps://0xem.ma/cve/2020/04/28/Source-hl2-relaunch-exec.html

All References (2)

→
https://0xem.ma/cve/2020/04/28/Source-hl2-relaunch-exec.htmlExploit · Third Party Advisory
→
https://0xem.ma/cve/2020/04/28/Source-hl2-relaunch-exec.htmlExploit · Third Party Advisory

Quick Facts

CVE IDCVE-2020-12242
CVSS Score7.8 / 10
SeverityHIGH
WeaknessCWE-78
CISA KEVNo
ExploitPOC
Affected1 vendor(s)
PublishedApr 27, 2020

Related CVEs (CWE-78)

CVE-2011-0271
10.0
CVE-2010-2445
10.0
CVE-2010-3757
10.0
CVE-2010-3754
10.0
CVE-2010-0418
10.0
CVE-2011-0372
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-12242 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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