CVE-2021-21311
Adminer Server-Side Request Forgery Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 20 October 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- EPSS
- 90.46% probability · 100th percentile
- CISA KEV
- Listed 29 September 2025 · due 20 October 2025
- Weakness
- CWE-918
- Affected
- adminer/adminer · debian/debian linux
- Source
- security-advisories@github.com
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6 ; https://nvd.nist.gov/vuln/detail/CVE-2021-21311
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.