CVE-2021-21311 in Adminer and Debian Products
Published on February 11, 2021
SSRF in adminer
Known Exploited Vulnerability
This Adminer Server-Side Request Forgery Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Adminer contains a server-side request forgery vulnerability that, when exploited, allows a remote attacker to obtain potentially sensitive information.
The following remediation steps are recommended / required by October 20, 2025: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vulnerability Analysis
CVE-2021-21311 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is a SSRF Vulnerability?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
CVE-2021-21311 has been classified to as a SSRF vulnerability or weakness.
Products Associated with CVE-2021-21311
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Affected Versions
vrana adminer Version >= 4.0.0, < 4.7.9 is affected by CVE-2021-21311Vulnerable Packages
The following package name and versions may be associated with CVE-2021-21311
| Package Manager | Vulnerable Package | Versions | Fixed In |
|---|---|---|---|
| composer | vrana/adminer | < 4.7.9 | 4.7.9 |
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.