CVE-2020-15530

Exp

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.

Published: 2020-07-05 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-15530 is rated Exploit Available (54.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.08%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-15530

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-15530

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-14 0.04% 0.08% +0.04%
2 2023-03-07 0.89% 0.04% -0.84%
3 2022-04-01 — 0.89% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-15530

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2020-15530

OS Trackers for CVE-2020-15530

vendor priority summary link
debian unimportant CVE-2020-15530 unimportant priority: Debian including 1 source packages (steam), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2020-15530
ubuntu medium CVE-2020-15530 medium priority: Ubuntu including 1 source packages (steam), 6 status rows across 6 suites (bionic, eoan, focal, trusty, upstream, xenial): not-affected 5, DNE 1. https://ubuntu.com/security/CVE-2020-15530

Affected software / configurations for CVE-2020-15530

Vendor Product Version Raw CPE
valvesoftware steam_client 2.10.91.91 cpe:2.3:a:valvesoftware:steam_client:2.10.91.91:*:*:*:*:*:*:*

References for CVE-2020-15530

cvelogic Threat Intelligence