CVE-2021-33879
Published: 06 June 2021
Summary
CVE-2021-33879 is a high-severity Download of Code Without Integrity Check (CWE-494) vulnerability in Tencent Gameloop. Its CVSS base score is 8.1 (High).
Operationally, ranked in the top 24.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-20553
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Policies can require integrity verification of software prior to installation, reducing risks from unverified downloads.
Blocks installation of components lacking a valid signature, mitigating download or installation of code without integrity checks.
Acquisition and maintenance portions of the strategy drive requirements for integrity verification of downloaded or supplied code.
Mandating integrity control and approved-only changes during development prevents incorporation of code or components lacking integrity validation.
Supply chain protection requires integrity verification of acquired components, directly reducing insertion or tampering of malicious code during delivery.
Reduces exposure to code obtained without integrity verification by requiring assurance processes that confirm authenticity and absence of tampering.
Tamper resistance and detection commonly include integrity verification of code and firmware obtained from external sources.
Component authenticity requires verifying origin/integrity of acquired firmware or software, directly preventing inclusion of code without integrity checks.