HOMEVULNERABILITIESCVE-2020-15530
HIGH

CVE-2020-15530

CWE-362Published: July 5, 2020· Updated: Jun 17, 2026

7.8
CVSS v3.1

Official Description

An issue was discovered in Valve Steam Client 2.10.91.91. The installer allows local users to gain NT AUTHORITY\SYSTEM privileges because some parts of %PROGRAMFILES(X86)%\Steam and/or %COMMONPROGRAMFILES(X86)%\Steam have weak permissions during a critical time window. An attacker can make this time window arbitrarily long by using opportunistic locks.

NVD Source

Technical Analysis

CVE-2020-15530 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.

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)
steam client
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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

ADVISORYhttp://daniels-it-blog.blogspot.com/2020/07/steam-arbitrary-code-execution-part-2.html
ADVISORYhttp://daniels-it-blog.blogspot.com/2020/07/steam-arbitrary-code-execution-part-2.html

All References (2)

→
http://daniels-it-blog.blogspot.com/2020/07/steam-arbitrary-code-execution-part-2.htmlExploit · Third Party Advisory
→
http://daniels-it-blog.blogspot.com/2020/07/steam-arbitrary-code-execution-part-2.htmlExploit · Third Party Advisory

Quick Facts

CVE IDCVE-2020-15530
CVSS Score7.8 / 10
SeverityHIGH
WeaknessCWE-362
CISA KEVNo
Affected1 vendor(s)
PublishedJul 5, 2020

Related CVEs (CWE-362)

CVE-2008-6598
10.0
CVE-2010-1228
10.0
CVE-2014-0703
10.0
CVE-2015-8556
10.0
CVE-2020-1660
9.9
CVE-2025-48751
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-15530 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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