Is CVE-2021-40889 actively exploited?

No active exploitation of CVE-2021-40889 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-40889 be exploited remotely?

Yes. CVE-2021-40889 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-40889?

CVE-2021-40889 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-40889

CRITICAL

CVE-2021-40889

CWE-94Published: October 11, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

CMSUno version 1.7.2 is affected by a PHP code execution vulnerability. sauvePass action in {webroot}/uno/central.php file calls to file_put_contents() function to write username in password.php file when a user successfully changed their password. The attacker can inject malicious PHP code into password.php and then use the login function to execute code.

NVD Source

Technical Analysis

CVE-2021-40889 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.