CVE-2021-21311
Published: September 29, 2025
Official Description
Adminer contains a server-side request forgery vulnerability that, when exploited, allows a remote attacker to obtain potentially sensitive information.
CISA KEV Advisory
Adminer Server-Side Request Forgery Vulnerability
Adminer contains a server-side request forgery vulnerability that, when exploited, allows a remote attacker to obtain potentially sensitive information.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Risk Analysis
Adminer contains a server-side request forgery (SSRF) vulnerability that can lead to the disclosure of sensitive information. The high EPSS score of 0.94214 and its presence in the KEV indicate a high probability of exploitation and active threats.
This vulnerability is actively exploited in the wild. Server-side request forgery can often be triggered remotely.
Organizations using Adminer should apply the latest security updates to patch this SSRF vulnerability. Review and restrict network access to Adminer instances to minimize exposure.
Technical Analysis
CVE-2021-21311 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2021-21311 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-21311 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1