CVE-2021-21311: Adminer Server-Side Request Forgery Vulnerability

Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-7d8001aa02d8, updated 2026-11-02T23:39:54.475Z.

CISA Known Exploited Vulnerabilities

Name: Adminer Server-Side Request Forgery Vulnerability
Vendor: Adminer
Product: Adminer
Added to the catalog: 2025-09-29
Due date for US federal agencies: 2025-10-20
Weaknesses: CWE-918
Catalog version: 2026.10.30

Adminer contains a server-side request forgery vulnerability that, when exploited, allows a remote attacker to obtain potentially sensitive information.

Required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status: Analyzed
Published: 2021-02-11T21:15:13.820
Last modified: 2026-06-17T03:35:16.213
Weaknesses: CWE-918

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.

Metric	Score	Severity	Vector	Scored by
CVSS 3.1	7.2	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N	[email protected] (Secondary)
CVSS 3.1	7.2	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N	[email protected] (Primary)
CVSS 2.0	6.4	MEDIUM	AV:N/AC:L/Au:N/C:P/I:P/A:N	[email protected] (Primary)

References

https://github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351 (Patch)
https://github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdf (Exploit, Third Party Advisory)
https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6 (Patch, Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2021/03/msg00002.html (Mailing List, Third Party Advisory)
https://packagist.org/packages/vrana/adminer (Product, Third Party Advisory)
https://github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351 (Patch)
https://github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdf (Exploit, Third Party Advisory)
https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6 (Patch, Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2021/03/msg00002.html (Mailing List, Third Party Advisory)
https://packagist.org/packages/vrana/adminer (Product, Third Party Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21311 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-21311

CVE record

Title (CNA): SSRF in adminer
Assigner: GitHub_M
State: PUBLISHED
Published: 2021-02-11T20:55:15.000Z
Updated: 2025-10-21T23:35:27.923Z
Problem types: CWE-918: Server-Side Request Forgery (SSRF)

References

Read on 2026-11-03T01:06:02.184Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/21xxx/CVE-2021-21311.json

Also known as / affected packages

GHSA-x5r2-hj5c-8jx6

Also known as: CVE-2021-21311. OSV.dev record, GitHub advisory.

Packagist vrana/adminer: introduced 0, fixed 4.7.9

Read on 2026-11-03T00:53:13.553Z under licence ghsa-cc-by-4.0@9e5f1b3c from https://api.osv.dev/v1/vulns/GHSA-x5r2-hj5c-8jx6

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

CWE-918: Server-Side Request Forgery (SSRF)

Isolate: Application-based Process Isolation (acts on Subroutine)
Restore: Restore Software (acts on Software)
Model: Asset Vulnerability Enumeration (acts on Software)
Harden: Trusted Library (acts on Subroutine)
Harden: Domain Logic Validation (acts on Subroutine)
Harden: Variable Initialization (acts on Subroutine)
Harden: Credential Scrubbing (acts on Subroutine)
Harden: Software Update (acts on Software)
Model: Software Inventory (acts on Software)

D3FEND ontology version 1.6.0.

Read on 2026-11-03T00:03:22.605Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-918.json

MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/

Sources and licences

CISA
Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.
CC0 1.0 Universal
National Vulnerability Database (NIST)
This product uses the NVD API but is not endorsed or certified by the NVD.
NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)
CVE Program, The MITRE Corporation
Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
CVE Program Terms of Use ("CVE Usage" licence)
GitHub Advisory Database via OSV.dev
GHSA-x5r2-hj5c-8jx6: GitHub Advisory Database, https://github.com/advisories/GHSA-x5r2-hj5c-8jx6. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/), provided as is, without warranties. Retrieved via OSV.dev (https://osv.dev/vulnerability/GHSA-x5r2-hj5c-8jx6), which enriches records; fields selected and reformatted by ransomware-tracker.com.
CC BY 4.0
MITRE D3FEND
MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/
MITRE D3FEND Terms of Use (site + knowledge graph); source repo MIT

Cite this page

Dragons Eye Ransomware Tracker, "CVE-2021-21311: Adminer Server-Side Request Forgery Vulnerability",
entity page, dataset version ref-7d8001aa02d8, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2021-21311 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-06-17T03:35:16.213.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2025-10-21T23:35:27.923Z.
Underlying source: GitHub Advisory Database, GHSA-x5r2-hj5c-8jx6, via OSV.dev, modified 2026-09-10T03:49:14.190623191Z.
Underlying source: MITRE D3FEND, ontology version 1.6.0.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.

CISA KEV index