CVE-2021-33879
HIGHDescription
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 to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 60% of all known CVEs.
References
Related Vulnerabilities
Other CWE-494 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-5398 | High | 7.5 | 88% | - | Fix |
| CVE-2022-40799 | High | 8.8 | 32% | KEV | - |
| CVE-2026-3502 | High | 7.8 | 5.8% | KEV | Fix |
| CVE-2018-19234 | High | 8.8 | 3.3% | - | Fix |
| CVE-2016-6567 | Critical | 9.8 | 2.9% | - | - |
| CVE-2016-6564 | High | 8.1 | 2.7% | - | - |
Common questions
How do I fix CVE-2021-33879?
Upgrade gameloop to 4.1.21.90 or later.
Is CVE-2021-33879 being actively exploited?
Not that we know of. CVE-2021-33879 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 60% of all scored CVEs.
How severe is CVE-2021-33879?
CVE-2021-33879 has a CVSS v3 base score of 8.1, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-33879 affect?
Published advisories record a fix for gameloop (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.