Cyber Resilience

CVE-2021-26236

HighPublic PoC

Published: 18 March 2021

Published
18 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0074 73.4th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-26236 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Faststone Image Viewer. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 26.6% 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

FastStone Image Viewer v.<= 7.5 is affected by a Stack-based Buffer Overflow at 0x005BDF49, affecting the CUR file parsing functionality (BITMAPINFOHEADER Structure, 'BitCount' file format field), that will end up corrupting the Structure Exception Handler (SEH). Attackers could exploit this…

more

issue to achieve code execution when a user opens or views a malformed/specially crafted CUR file.

CWE(s)

Related Threats

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

Affected Assets

faststone
image viewer
≤ 7.5

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.

addresses: CWE-787

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

References