What is CVE-2021-4251?

CVE-2021-4251 is a low-severity vulnerability in As Project, classified under CWE-707. CVSS score: 3.5/10. Published 2022-12-18.

How severe is CVE-2021-4251?

Low severity. CVSS v3 base score is 3.5 out of 10.

Vulnerability in As Project

CVE-2021-4251

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.

Published 2022-12-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (31.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-707

References

github.com/andrewsauder/as/commit/4acad1e3d2c34c017473ceea442fb3e3e078b2bd (Patch, Third Party Advisory)
vuldb.com/ (Third Party Advisory)

Frequently asked questions

What is CVE-2021-4251?: CVE-2021-4251 is a low-severity vulnerability in As Project, classified under CWE-707. CVSS score: 3.5/10. Published 2022-12-18.
How severe is CVE-2021-4251?: Low severity. CVSS v3 base score is 3.5 out of 10.