CVE-2021-29625 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in vrana/adminer. 1 public exploit reference exists, so weaponization risk is real. A fix is available for vrana/adminer — see the affected versions and patch details below.
XSS in doc_link
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2021-29625 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
vrana/adminerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Users of MySQL, MariaDB, PgSQL and SQLite are affected. XSS is in most cases prevented by strict CSP in all modern browsers. The only exception is when Adminer is using a pdo_ extension to communicate with the database (it is used if the native extensions are not enabled). In browsers without CSP, Adminer versions 4.6.1 to 4.8.0 are affected.
Patches
Patched by 4043092, included in version 4.8.1.
Workarounds
Do both:
- Use browser supporting strict CSP.
- Enable the native PHP extensions (e.g.
mysqli) or disable displaying PHP errors (display_errors).
References
https://sourceforge.net/p/adminer/bugs-and-features/797/
For more information
If you have any questions or comments about this advisory:
- Comment at 4043092.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | vrana/adminer | ≥ 4.7.8&&< 4.8.1 | 4.8.1composer require vrana/adminer:^4.8.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vrana/adminer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update vrana/adminer to 4.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29625 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-29625 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-29625. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2021-29625
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2021-29625 -u https://target- Template
- Adminer <=4.8.0 - Cross-Site Scripting
- Severity
- medium
- Impact
- Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into the Adminer interface, potentially leading to session hijacking, defacement, or theft of sensitive information.
- Remediation
- This vulnerability is patched in version 4.8.1. As workarounds, one can use a browser supporting strict CSP or enable the native PHP extensions (e.g. `mysqli`) or disable displaying PHP errors (`display_errors`).
Template by ProjectDiscovery nuclei-templates (daffainfo), MIT licensed. View the full template. Scan only systems you are authorised to test.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2021-29625 in your dependencies?
O3 Security finds CVE-2021-29625 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.