CVE-2021-21826
Published: 20 August 2021
Summary
CVE-2021-21826 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Att Xmill. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 35.5% 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-2021-8997
Vulnerability details
A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7. Within `DecodeTreeBlock` which is called during the decompression of an XMI file, a UINT32 is loaded from the file and used as trusted…
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input as the length of a buffer. An attacker can provide a malicious file to trigger this vulnerability.
- 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.
Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.