Known exploited vulnerability
CVE-2021-21311
The short answer
CVE-2021-21311 affects vrana adminer and is rated high (CVSS 7.2). CISA added it to the Known Exploited Vulnerabilities catalog on 2025-09-29: attackers are using it, so patch it first. Fixed versions are published for vrana/adminer (4.7.9).
What it is
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.
Weakness: CWE-918.
Severity
7.2 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Exploited (CISA KEV)
Yes, since Sep 29, 2025
Federal due date Oct 20, 2025
EPSS, next 30 days
98%
Higher than 100% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected packages and fixed versions
| Package | Ecosystem | Fixed in | Advisory |
|---|---|---|---|
| vrana/adminer | Packagist | 4.7.9 | GHSA-x5r2-hj5c-8jx6 |
Is it in your code? Drop your lockfile into the free vulnerability check, or let vulnerability watch check your repository every day and open the upgrade as a pull request.
Affected products
adminer. NVD's record lists the exact affected versions.
References
- github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351 Patch
- github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdf ExploitThird Party Advisory
- github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6 PatchThird Party Advisory
- lists.debian.org/debian-lts-announce/2021/03/msg00002.html Mailing ListThird Party Advisory
- packagist.org/packages/vrana/adminer ProductThird Party Advisory
- github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351 Patch
- github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdf ExploitThird Party Advisory
- github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6 PatchThird Party Advisory
- lists.debian.org/debian-lts-announce/2021/03/msg00002.html Mailing ListThird Party Advisory
- packagist.org/packages/vrana/adminer ProductThird Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21311 US Government Resource
Questions
Is CVE-2021-21311 being exploited?
Yes. CISA added CVE-2021-21311 to its Known Exploited Vulnerabilities catalog on 2025-09-29, with a federal remediation due date of 2025-10-20.
How do I fix CVE-2021-21311?
Upgrade to a fixed version: vrana/adminer (Packagist) 4.7.9. CISA's 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.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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Every vendor in CISA's KEV catalog, with its count.
Adminer exploited vulnerabilities
Everything CISA lists as exploited for Adminer.
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