Is CVE-2021-42645 actively exploited?

No active exploitation of CVE-2021-42645 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-42645 be exploited remotely?

Yes. CVE-2021-42645 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-42645?

CVE-2021-42645 has a CVSS score of 10.0 (CRITICAL).

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CRITICAL

CVE-2021-42645

CWE-434Published: May 10, 2022· Updated: Jun 17, 2026

10.0

CVSS v3.1

Official Description

CMSimple_XH 1.7.4 is affected by a remote code execution (RCE) vulnerability. To exploit this vulnerability, an attacker must use the "File" parameter to upload a PHP payload to get a reverse shell from the vulnerable host.

NVD Source

Technical Analysis

CVE-2021-42645 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 10.0.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.