CVE-2021-21311

HIGH KEV NUCLEI LAB

Adminer 4.0.0-4.7.8 - Server-Side Request Forgery

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2021-21311 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added September 29, 2025. EIP tracks 4 public exploits from researchers including omoknooni, Sudo-WP. A Nuclei detection template is also available.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2021-21311, an SSRF vulnerability in Adminer versions 4.0.0 to 4.7.8. The exploit uses a crafted HTTP request to trigger an SSRF via the 'auth[server]' parameter, redirecting the server to an attacker-controlled endpoint.

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.

Exploits (4)

nomisec WORKING POC 3 stars
by omoknooni · poc
https://github.com/omoknooni/CVE-2021-21311

This repository contains a functional exploit for CVE-2021-21311, an SSRF vulnerability in Adminer versions 4.0.0 to 4.7.8. The exploit uses a crafted HTTP request to trigger an SSRF via the 'auth[server]' parameter, redirecting the server to an attacker-controlled endpoint.

Classification
Working Poc 95%
Attack Type
Ssrf
Complexity
Moderate
Reliability
Reliable
Target: Adminer 4.0.0 - 4.7.8
No auth needed
Prerequisites: Target Adminer instance accessible · Attacker-controlled server to handle redirects
devstral-2 · analyzed Feb 18, 2026 Full analysis →
nomisec WRITEUP
by Sudo-WP · poc
https://github.com/Sudo-WP/sudowp-adminer

This repository is a security-hardened fork of the Adminer WordPress plugin, specifically addressing CVE-2021-21311 (SSRF vulnerability). It includes detailed technical documentation on the vulnerability, mitigation strategies, and security hardening measures implemented.

Classification
Writeup 95%
Attack Type
Ssrf
Complexity
Moderate
Reliability
Reliable
Target: Adminer WordPress plugin (versions prior to the security-hardened fork)
Auth required
Prerequisites: Access to WordPress admin panel · Adminer plugin installed and activated
devstral-2 · analyzed Feb 19, 2026 Full analysis →
vulncheck_xdb WORKING POC
remote
https://github.com/llhala/CVE-2021-21311

This repository contains a functional exploit for CVE-2021-21311, an SSRF vulnerability in Adminer. The exploit sets up an HTTP server to capture SSRF responses and crafts a malicious request to trigger the vulnerability.

Classification
Working Poc 95%
Attack Type
Ssrf
Complexity
Moderate
Reliability
Reliable
Target: Adminer versions 4.0.0 to 4.7.8
No auth needed
Prerequisites: Network access to the target Adminer instance · Ability to host an HTTP server for capturing SSRF responses
devstral-2 · analyzed Feb 26, 2026 Full analysis →
inthewild WORKING POC
poc
https://github.com/llhala/cve-2021-21311

This repository contains a functional exploit for CVE-2021-21311, an SSRF vulnerability in Adminer. The exploit sets up a local HTTP server to capture SSRF responses and crafts a malicious request to the vulnerable Adminer instance to trigger the SSRF.

Classification
Working Poc 95%
Attack Type
Ssrf
Complexity
Moderate
Reliability
Reliable
Target: Adminer versions 4.0.0 to 4.7.8
No auth needed
Prerequisites: Access to the vulnerable Adminer instance · Ability to set up a local HTTP server to capture responses
devstral-2 · analyzed Feb 23, 2026 Full analysis →

Nuclei Templates (1)

Adminer <4.7.9 - Server-Side Request Forgery
HIGHby Adam Crosser,pwnhxl
Shodan: title:"Login - Adminer" || cpe:"cpe:2.3:a:adminer:adminer" || http.title:"login - adminer"
FOFA: app="Adminer" && body="4.7.8" || title="login - adminer" || app="adminer" && body="4.7.8"

References (6)

Core 6
Core References
Patch, Third Party Advisory x_refsource_confirm
https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6
Exploit, Third Party Advisory x_refsource_misc
https://github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdf
Product, Third Party Advisory x_refsource_misc
https://packagist.org/packages/vrana/adminer
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/03/msg00002.html

Scores

CVSS v3 7.2
EPSS 0.9411
EPSS Percentile 99.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation active
Automatable yes
Technical Impact partial

Details

CISA KEV 2025-09-29
VulnCheck KEV 2022-05-04
ENISA EUVD EUVD-2021-0576
CWE
CWE-918
Status published
Products (3)
adminer/adminer 4.0.0 - 4.7.9
debian/debian_linux 9.0
vrana/adminer 0 - 4.7.9Packagist
Published Feb 11, 2021
KEV Added Sep 29, 2025
Tracked Since Feb 18, 2026