Is CVE-2021-20617 actively exploited?

Yes. CVE-2021-20617 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-20617 be exploited remotely?

The attack vector of CVE-2021-20617 has not been classified yet.

What is the CVSS score of CVE-2021-20617?

CVE-2021-20617 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-20617

UNKNOWNCISA KEVIN THE WILD

CVE-2021-20617

Published: April 11, 2026

EPSS:51.19%probability of exploitation in 30 daysPercentile:97.9th

Official Description

Improper access control vulnerability in acmailer ver. 4.0.1 and earlier, and acmailer DB ver. 1.1.3 and earlier allows remote attackers to execute an arbitrary OS command, or gain an administrative privilege which may result in obtaining the sensitive information on the server via unspecified vectors.

NVD Source

Technical Analysis

CVE-2021-20617 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-20617 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.