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
- 98.46% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 29 September 2025 · due 20 October 2025
- Weakness
- CWE-918
- Affected
- adminer/adminer · debian/debian linux
- Source
- security-advisories@github.com
EPSS moved from 98.5% on 24 September 2026 to 98.5% on 30 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
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, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.