CVE-2021-21311

Name: CVE-2021-21311
Creator: NVD / NIST
Published: 2021-02-11T21:15:13.82+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.2/10Actively ExploitedEPSS 90.46%

Last modified Jun 17, 2026

CVE-2021-21311 is a high-severity vulnerability rated 7.2/10 on the CVSS scale. Adminer is an open-source database management in a single PHP file. In adminer from version 4.0.0 and before 4.7.9 there is a server-side request forgery vulnerability. CISA has confirmed active exploitation in the wild. EPSS estimates a 90.46% chance of exploitation in the next 30 days.

Description

Adminer is an open-source database management in a single PHP file. In adminer from version 4.0.0 and before 4.7.9 there is a server-side request forgery vulnerability. Users of Adminer versions bundling all drivers (e.g. `adminer.php`) are affected. This is fixed in version 4.7.9.

Metrics

CVSS 3.1

7.2/10

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

EPSS Probability

90.46%

99.8th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Oct 20, 2025.

Weakness Enumeration

CWE-918

Affected Software

Vendor	Product	Versions
Adminer	Adminer	>= 4.0.0, < 4.7.9
Debian	Debian Linux	9.0

References

https://github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351Patch
https://github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdfExploit, Third Party Advisory
https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00002.htmlMailing List, Third Party Advisory
https://packagist.org/packages/vrana/adminerProduct, Third Party Advisory
https://github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351Patch
https://github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdfExploit, Third Party Advisory
https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00002.htmlMailing List, Third Party Advisory
https://packagist.org/packages/vrana/adminerProduct, Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21311US Government Resource

Timeline

Published: Feb 11, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-21311?

How severe is CVE-2021-21311?

CVE-2021-21311 has a CVSS score of 7.2/10 (HIGH severity). The EPSS model estimates a 90.46% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-21311?

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-2021-21311?

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

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Source: NVD / NIST