Cyber Resilience

CVE-2021-3405

MediumPublic PoC

Published: 23 February 2021

Published
23 February 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.0208 84.3th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3405 is a medium-severity Out-of-bounds Write (CWE-787) vulnerability in Fedoraproject Fedora. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 15.7% 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

Vulnerability details

A flaw was found in libebml before 1.4.2. A heap overflow bug exists in the implementation of EbmlString::ReadData and EbmlUnicodeString::ReadData in libebml.

CWE(s)
CWE-787

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

matroska
libebml
≤ 1.4.2
fedoraproject
fedora
32, 33, 34
debian
debian linux
9.0

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.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References