Security readout for executives and security teams
Plain-English summary
Adminer versions before 4.7.9 can be abused to make the server send requests it should not. This matters because Adminer often sits near databases and internal systems. CISA lists this CVE in KEV, so treat exposed or outdated instances as urgent.
Executive priority
Prioritize remediation for any internet-reachable Adminer instance. KEV status means this is not theoretical, and Adminer’s proximity to database administration increases business risk.
Technical view
CVE-2021-21311 is a server-side request forgery vulnerability in Adminer 4.0.0 through versions before 4.7.9, affecting all-driver bundles such as adminer.php. The CVSS 3.1 score is 7.2 with network attack vector, no privileges, and changed scope.
Likely exposure
Exposure is most likely where Adminer 4.0.0 to before 4.7.9 is deployed, especially bundled all-driver adminer.php files reachable over a network.
Exploitation context
CISA KEV indicates known exploitation. The provided sources do not describe current campaign scale, attacker tooling, or specific victim sectors.
Researcher notes
Evidence supports affected range, SSRF class, fixed version, and KEV status. The bundle does not include exploit details, campaign attribution, or complete operational mitigations beyond upgrading and distribution updates.
Mitigation direction
- Upgrade Adminer to version 4.7.9 or later.
- Apply distribution security updates, including Debian packages where relevant.
- Inventory and remove obsolete bundled adminer.php deployments.
- Restrict access to Adminer while patching.
- Check vendor guidance for any environment-specific hardening.
Validation and detection
- Identify Adminer files and package versions across web roots and containers.
- Confirm no deployed Adminer version is below 4.7.9.
- Verify whether deployments use all-driver bundles such as adminer.php.
- Review internet-facing assets for exposed Adminer pages.
- Check patch status against vendor and distribution advisories.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-918: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCloud metadata behavior lookup
The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-21311 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.2 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N3.92.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.2HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/vrana/adminer/security/advisories/GHSA-x5r2-hj5c-8jx6CVE reference · x_refsource_CONFIRM
- https://github.com/vrana/adminer/files/5957311/Adminer.SSRF.pdfCVE reference · x_refsource_MISC
- https://packagist.org/packages/vrana/adminerCVE reference · x_refsource_MISC
- https://github.com/vrana/adminer/commit/ccd2374b0b12bd547417bf0dacdf153826c83351CVE reference · x_refsource_MISC
- [debian-lts-announce] 20210302 [SECURITY] [DLA 2580-1] adminer security updateCVE reference · mailing-list, x_refsource_MLIST
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21311CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Server-Side Request Forgery (SSRF)
Server-Side Request Forgery (SSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.