CVE-2021-21311
HighExploitedPublic exploitSSRF in adminer
Published Feb 11, 2021 · Updated Sep 10, 2026 · Also known as DEBIAN-CVE-2021-21311, DLA-2580-1, GHSA-x5r2-hj5c-8jx6, UBUNTU-CVE-2021-21311
Key Facts
Patch immediately- CVE-2021-21311 is a high-severity vulnerability (CVSS 7.2 v3.1) affecting Adminer, Debian Linux, vrana/adminer (composer).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 4, 2022. Public exploit code is available.
- EPSS estimates a 98% probability of exploitation in the next 30 days.
- Fixed versions are available, including Adminer 4.2.1-1ubuntu1+esm1, Adminer 4.2.5-3+deb9u2, Adminer 4.6.2-1ubuntu0.1~esm1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
98%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-21311 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Sep 29, 2025 | Oct 20, 2025 | Not reported |
| Industry KEV feed | May 4, 2022 | Oct 20, 2025 | Not reported |
| CIRCL KEV | Sep 29, 2025 | Oct 20, 2025 | Not reported |
| ENISA EUVD | Sep 29, 2025 | n/a | Not reported |
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.
Affected Products
21 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| AdminerAdminer | >= >= 4.0.0, < 4.7.9 | 4.7.9 |
| Debian LinuxDebian | 9.0 | n/a |
| vrana/adminercomposer | See advisory | 4.7.9 |
Patched Releases
Adminer
4.2.1-1ubuntu1+esm1, 4.2.5-3+deb9u2, 4.6.2-1ubuntu0.1~esm1, 4.7.6-1ubuntu0.1~esm1, 4.7.9-1, 4.7.9
vrana/adminer
4.7.9
Timeline
Publicly disclosed
Feb 11, 2021
Added to Industry KEV feed
May 4, 2022
Added to CISA KEV
Sep 29, 2025
Added to CIRCL KEV
Sep 29, 2025
Added to ENISA EUVD
Sep 29, 2025
Last updated
Sep 10, 2026
Weakness Type
- CWE-918 Server-Side Request Forgery (SSRF)
References
- advisoryGHSA advisory
- advisory[debian-lts-announce] 20210302 [SECURITY] [DLA 2580-1] adminer security update
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2021-21311
- advisoryhttps://packagist.org/packages/vrana/adminer
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2021-21311
FAQ
Common Questions.
Adminer is an open-source database management in a single PHP file.
Affected: Adminer versions >= >= 4.0.0, < 4.7.9; Debian Linux versions 9.0; vrana/adminer (composer). The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 4, 2022.
Yes. It was added on Sep 29, 2025 with a federal remediation due date of Oct 20, 2025.
Public exploit code is available.
Fixed versions are available, including Adminer 4.2.1-1ubuntu1+esm1, Adminer 4.2.5-3+deb9u2, Adminer 4.6.2-1ubuntu0.1~esm1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2021-21311 Running On Your Attack Surface?
Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.
Request A Demo