CVE-2021-4251

Name: CVE-2021-4251
Creator: NVD / NIST
Published: 2022-12-18T22:15:10.167+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.39%

Last modified Jun 17, 2026

CVE-2021-4251 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. A vulnerability classified as problematic was found in as. This vulnerability affects the function getFullURL of the file include.cdn.php. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

A vulnerability classified as problematic was found in as. This vulnerability affects the function getFullURL of the file include.cdn.php. The manipulation leads to cross site scripting. The attack can be initiated remotely. The name of the patch is 4acad1e3d2c34c017473ceea442fb3e3e078b2bd. It is recommended to apply a patch to fix this issue. The identifier of this vulnerability is VDB-216208.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.39%

30.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-707

Affected Software

Vendor	Product	Versions
As Project	As	< 2021-11-03

References

https://github.com/andrewsauder/as/commit/4acad1e3d2c34c017473ceea442fb3e3e078b2bdPatch, Third Party Advisory
https://vuldb.com/?id.216208Third Party Advisory
https://github.com/andrewsauder/as/commit/4acad1e3d2c34c017473ceea442fb3e3e078b2bdPatch, Third Party Advisory
https://vuldb.com/?id.216208Third Party Advisory

Timeline

Published: Dec 18, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-4251?

How severe is CVE-2021-4251?

CVE-2021-4251 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2021-4251?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-4251?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST