Cyber Resilience

CVE-2021-46686

CriticalRCE

Published: 18 February 2025

Published
18 February 2025
Modified
15 April 2026
KEV Added
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Patch
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CVSS Score v3 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0046 64.3th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-46686 is a critical-severity OS Command Injection (CWE-78) vulnerability in Acmailer (inferred from references). Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 35.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Improper neutralization of special elements used in an OS command ('OS Command Injection') issue exists in acmailer CGI ver.4.0.3 and earlier and acmailer DB ver.1.1.5 and earlier. If this vulnerability is exploited, an arbitrary OS command may be executed by…

more

an attacker.

CWE(s)
CWE-78

Related Threats

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

Affected Assets

Acmailer
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inferred from references and description; NVD did not file a CPE for this CVE

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.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

References