External risk intelligence

Adminer Database Management Vulnerability

CVE advisoryKnown Exploit

CVE-2021-21311

A server-side request forgery vulnerability exists in Adminer, a database management tool. This flaw affects Adminer versions bundling all drivers and could allow attackers to access sensitive information. Organizations using vulnerable versions face business risk due to potential unauthorized data access.

4Halo Surface Signal

Server-Side Request Forgery

Adminer

4.0.0 to before 4.7.99.0

External exposure likelihood

Halo Surface Signal score for CVE-2021-21311

Adminer is a web-based database management tool. While it is often used internally, it is commonly deployed as a standalone, internet-reachable web application or management interface to facilitate database access, making it a frequent target for public-facing discovery and interaction.

Horizon Alert

Summary of the vulnerability and why it matters

Adminer, a database management tool distributed as a single PHP file, contains a flaw that can enable attackers to conduct server-side requests. This vulnerability affects versions of Adminer that bundle all database drivers. The ability for an attacker to initiate server-side requests could lead to unauthorized access or manipulation of data.

Adminer database management tool
Server-side request forgery flaw
Unauthorized data access or manipulation

Attack Path

How an attacker could exploit the issue

Adminer, a PHP-based database management tool, has a vulnerability that could allow unauthorized access to internal systems. This flaw, present in versions prior to 4.7.9, enables attackers to trick the application into making requests to arbitrary network locations. This could potentially expose sensitive information or allow further access to the network. Organizations using affected versions of Adminer, particularly those bundling all drivers, should be aware of this risk.

A web server running Adminer is exposed.
An attacker sends a crafted request to Adminer.
Adminer makes a request to an attacker-controlled location.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability affects Adminer versions prior to 4.7.9 when using bundles that include all drivers. It allows for a server-side request forgery, potentially enabling unauthorized access to sensitive information. Organizations utilizing affected versions should consider immediate mitigation or updates to address the associated risks. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has listed this vulnerability as actively exploited.

Attackers with low skill can exploit.
No special access or conditions needed.
High business risk, treat as urgent.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability, identified by the CVE ID, impacts organizations using specific versions of Adminer, an open-source database management tool. Exploitation could allow unauthorized access to sensitive information through server-side request forgery. The vendor has released a corrected version to address this issue.

Find assets using vulnerable Adminer versions.
Reduce exposure of affected systems.
Apply vendor fix and validate.
Monitor for related activity.

Frequently asked questions

What is Adminer and what kind of vulnerability does it have?

Adminer is an open-source database management tool provided as a single PHP file. It has a server-side request forgery (SSRF) vulnerability in versions prior to 4.7.9, specifically affecting those that bundle all database drivers. This flaw could allow attackers to make the server send requests to unintended network locations.

What is the weakness class for CVE-2021-21311 and how does it manifest?

The weakness class for CVE-2021-21311 is CWE-918, which corresponds to Server-Side Request Forgery. This vulnerability allows an attacker to induce the server-side application to make HTTP requests to an arbitrary domain of the attacker's choosing. This can lead to the disclosure of remote file contents or the interaction with arbitrary backend or cloud APIs.

How can an attacker exploit Adminer's SSRF vulnerability and what is the scope?

An attacker can exploit this vulnerability by sending a crafted request to an affected Adminer instance. The vulnerability allows the application to make requests to attacker-controlled locations. The scope of the impact is broadened because the request originates from the server itself, potentially allowing access to internal resources or bypassing network restrictions that would normally protect them.

What is the relevance of CVE-2021-21311 and has it been exploited in the wild?

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has identified CVE-2021-21311 as a known exploited vulnerability, indicating active exploitation in the wild. Its inclusion in such a catalog highlights its significant threat and potential for misuse by malicious actors.

What steps should be taken to respond to the Adminer SSRF vulnerability?

To address this vulnerability, organizations should identify all assets running vulnerable versions of Adminer, particularly those bundling all drivers. It is crucial to reduce the exposure of these systems, apply the vendor-supplied fix in version 4.7.9 or later, and validate that the update has been successfully implemented. Continuous monitoring for any suspicious activity related to these systems is also recommended.

References

Written by Nicholas Merritt

External-surface CVE analysis and Halo Surface Signal prioritization for Halo Threat Intelligence.