CVE-2021-33879 json
Tencent GameLoop before 4.1.21.90 downloaded updates over an insecure HTTP connection.
published 2021-06-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-20553
- cvss
- 8.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- tencent gameloop 4.1.21.90
Exploit prediction
1.20% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/mmiszczyk/cve-2021-33879 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-494 Download of Code Without Integrity Check
References
-
github.com
/mmiszczyk/cve-2021-33879
exploit, third-party-advisory
-
gameloop.com
vendor-advisory
Sources
- CVE List CVE-2021-33879
- NVD CVE-2021-33879
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