Cyber Resilience

CVE-2021-42645

CriticalPublic PoC

Published: 10 May 2022

Published
10 May 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0708 91.7th percentile
Risk Priority 24 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-42645 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Cmsimple-Xh Cmsimple Xh. Its CVSS base score is 10.0 (Critical).

Operationally, ranked in the top 8.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

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

Affected Assets

cmsimple-xh
cmsimple xh
1.7.4

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.

addresses: CWE-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

addresses: CWE-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

References