How severe is CVE-2021-42645?

CVE-2021-42645 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42645 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42645?

CVE-2021-42645 affects Cmsimple-xh Cmsimple Xh. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42645?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-42645 published?

CVE-2021-42645 was published on 2022-05-10 and last updated on 2026-06-17.

CVE-2021-42645

CVE-2021-42645 is a critical-severity vulnerability in Cmsimple-xh Cmsimple Xh with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-434.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
CVSS v2: 10.0
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Cmsimple-xh Cmsimple Xh
Published: 2022-05-10
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-42645?: 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.
How severe is CVE-2021-42645?: CVE-2021-42645 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42645 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42645?: CVE-2021-42645 affects Cmsimple-xh Cmsimple Xh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42645?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-42645 published?: CVE-2021-42645 was published on 2022-05-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cmsimple-xh:cmsimple_xh:1.7.4:*:*:*:*:*:*:*

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