SB2018110907 - Security restrictions bypass in Steam



SB2018110907 - Security restrictions bypass in Steam

Published: November 9, 2018

Security Bulletin ID SB2018110907
Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Security restrictions bypass (CVE-ID: N/A)

The vulnerability allows a remote authenticated attacker to bypass security restrictions.

The weakness exists in a Steam web API located at partner.steamgames.com/partnercdkeys/assignkeys/ due to attacker can go through all Steam games IDs, as the appid and keyid parameters were easy to guess. A remote authenticated use the /partnercdkeys/assignkeys/ endpoint on partner.steamgames.com with keycount parameter to "0", bypass the API's limitations, retrieve a file with CD keys belonging to any game and download previously-generated CD keys for a game which they would not normally have access.

Remediation

Install update from vendor's website.