CVE-2020-15530 : What You Need to Know

An issue was discovered in Valve Steam Client 2.10.91.91 that allows local users to gain NT AUTHORITY\SYSTEM privileges due to weak permissions in certain directories during a critical time window.

Understanding CVE-2020-15530

This CVE identifies a privilege escalation vulnerability in Valve Steam Client version 2.10.91.91.

What is CVE-2020-15530?

The vulnerability in Valve Steam Client 2.10.91.91 enables local users to elevate their privileges to NT AUTHORITY\SYSTEM by exploiting weak permissions in specific directories during a critical time frame.

The Impact of CVE-2020-15530

The vulnerability allows attackers to extend the critical time window by utilizing opportunistic locks, potentially leading to unauthorized system access and manipulation.

Technical Details of CVE-2020-15530

Valve Steam Client 2.10.91.91 is susceptible to a privilege escalation flaw.

Vulnerability Description

The installer of Valve Steam Client 2.10.91.91 grants local users the ability to escalate their privileges to NT AUTHORITY\SYSTEM due to inadequate permissions in %PROGRAMFILES(X86)%\Steam and/or %COMMONPROGRAMFILES(X86)%\Steam during a specific time window.

Affected Systems and Versions

Product: Valve Steam Client
Vendor: Valve
Version: 2.10.91.91

Exploitation Mechanism

Attackers can exploit weak permissions in critical directories to gain NT AUTHORITY\SYSTEM privileges, with the potential to extend the exploitation window using opportunistic locks.

Mitigation and Prevention

Immediate Steps to Take:

Restrict access to critical directories to authorized users only
Monitor system permissions and access regularly

Long-Term Security Practices:

Implement the principle of least privilege to limit user access
Conduct regular security audits and vulnerability assessments

Patching and Updates:

Apply patches and updates provided by Valve to address the privilege escalation vulnerability in Steam Client.