How severe is CVE-2018-19420?

CVE-2018-19420 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2018-19420 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-19420?

CVE-2018-19420 affects Get-simple Getsimple Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-19420?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-19420 published?

CVE-2018-19420 was published on 2018-11-21 and last updated on 2026-06-17.

CVE-2018-19420

CVE-2018-19420 is a low-severity vulnerability in Get-simple Getsimple Cms with a CVSS 3.x base score of 3.8. 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: Low (CVSS 3.x base score 3.8)
CVSS v2: 4.0
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Get-simple Getsimple Cms
Published: 2018-11-21
Last modified: 2026-06-17

Description

In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.

Frequently asked questions

What is CVE-2018-19420?: In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.
How severe is CVE-2018-19420?: CVE-2018-19420 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2018-19420 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-19420?: CVE-2018-19420 affects Get-simple Getsimple Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-19420?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-19420 published?: CVE-2018-19420 was published on 2018-11-21 and last updated on 2026-06-17.

References

https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1301

Affected products (1)

cpe:2.3:a:get-simple:getsimple_cms:3.3.15:*:*:*:*:*:*:*

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