What is CVE-2021-21311?

CVE-2021-21311 is a high-severity vulnerability in Vrana Adminer, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.2/10. Published 2021-02-11.

How severe is CVE-2021-21311?

High severity. CVSS v3 base score is 7.2 out of 10.

Is CVE-2021-21311 known to be exploited?

Yes. CVE-2021-21311 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-09-29), indicating it is being actively exploited. 40 public proof-of-concept repositories are indexed.

SSRF in Vrana Adminer

CVE-2021-21311

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`) ar…

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.941 (99.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Vrana Adminer — versions >= 4.0.0, < 4.7.9

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2025-09-29. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2025-10-20.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6 (x_refsource_CONFIRM)
github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdf (x_refsource_MISC)
packagist.org/packages/vrana/adminer (x_refsource_MISC)
github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351 (x_refsource_MISC)
[debian-lts-announce] 20210302 [SECURITY] [DLA 2580-1] adminer security update (mailing-list, x_refsource_MLIST)

Frequently asked questions

What is CVE-2021-21311?: CVE-2021-21311 is a high-severity vulnerability in Vrana Adminer, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.2/10. Published 2021-02-11.
How severe is CVE-2021-21311?: High severity. CVSS v3 base score is 7.2 out of 10.
Is CVE-2021-21311 known to be exploited?: Yes. CVE-2021-21311 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-09-29), indicating it is being actively exploited. 40 public proof-of-concept repositories are indexed.