Cyber Resilience

CVE-2021-42203

HighPublic PoC

Published: 02 June 2022

Published
02 June 2022
Modified
21 November 2024
KEV Added
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Patch
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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 0.0076 73.8th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-42203 is a high-severity Use After Free (CWE-416) vulnerability in Swftools Swftools. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 26.2% 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 swftools through 20201222. A heap-use-after-free exists in the function swf_FontExtract_DefineTextCallback() located in swftext.c. It allows an attacker to cause code execution.

CWE(s)
CWE-416

Related Threats

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

Affected Assets

swftools
swftools
≤ 2020-12-22

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-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

References