CVE-2021-33879: Tencent Gameloop

High severity, CVSS 8.1. EPSS: 1% chance of exploitation in the next 30 days.

Tencent GameLoop before 4.1.21.90 downloaded updates over an insecure HTTP connection. A malicious attacker in an MITM position could spoof the contents of an XML document describing an update package, replacing a download URL with one pointing to an arbitrary Windows executable. Because the only integrity check would be a comparison of the downloaded file's MD5 checksum to the one contained within the XML document, the downloaded executable would then be executed on the victim's machine.

Affected products

• Tencent Gameloop: before 4.1.21.90 (fixed in 4.1.21.90)

Published 2021-06-06. Last modified 2026-06-17.