What is the CVSS score of CVE-2021-46686?

CVE-2021-46686 has a CVSS 3.0 base score of 9.8 (Critical). CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.6%.

How to fix or mitigate CVE-2021-46686?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Validate that input sanitization is in place for all user-controlled parameters.

CVE-2021-46686

CRITICAL

OS Command Injection (CWE-78)

2025-02-18 vultures@jpcert.or.jp

Command Injection

9.8

CVSS 3.0 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:27 vuln.today

CVE Published

Feb 18, 2025 - 00:15 nvd

CRITICAL 9.8

DescriptionCVE.org

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 an attacker.

AnalysisAI

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. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as OS Command Injection (CWE-78), which allows attackers to execute arbitrary operating system commands on the host. 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 an attacker.

Affected ProductsAI

See vendor advisory for affected versions.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Avoid passing user input to shell commands. Use language-specific APIs instead of shell execution. Apply strict input validation with allowlists.