Cyber Resilience

CVE-2021-39518

MediumPublic PoC

Published: 20 September 2021

Published
20 September 2021
Modified
21 November 2024
KEV Added
—
Patch
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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 0.0027 51.0th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-39518 is a medium-severity Out-of-bounds Write (CWE-787) vulnerability in Jpeg Libjpeg. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 49.0% 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

An issue was discovered in libjpeg through 2020021. LineBuffer::FetchRegion() in linebuffer.cpp has a heap-based buffer overflow.

CWE(s)
CWE-787

Related Threats

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

Affected Assets

jpeg
libjpeg
≤ 2020021

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