CVE-2021-33879
CVE-2021-33879 is a high-severity vulnerability in Tencent Gameloop with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-494.
Key facts
- Severity: High (CVSS 3.x base score 8.1)
- CVSS v2: 6.8
- EPSS exploit prediction: 1% (59th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-494
- Affected product: Tencent Gameloop
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2021-33879?
- 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.
- How severe is CVE-2021-33879?
- CVE-2021-33879 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-33879 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-33879?
- CVE-2021-33879 affects Tencent Gameloop. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-33879?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-33879 published?
- CVE-2021-33879 was published on 2021-06-06 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:tencent:gameloop:*:*:*:*:*:*:*:*
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