CVE-2017-20254: Joomla User Bench SQL Injection Vulnerability (CVSS 8.2)

Technical summary

The User Bench component for Joomla! 1.0 fails to properly sanitize user input in the userid parameter of the detail view. The vulnerability exists in the request path index.php?option=com_userbench&view=detail&userid=[payload]. An unauthenticated attacker can inject SQL syntax through this parameter, leading to arbitrary SQL query execution. The vulnerable code does not use parameterized queries or input validation, allowing direct manipulation of the SQL WHERE clause or subsequent query logic. This enables information disclosure attacks targeting the component's database schema and contents.

Business impact

A successful exploitation could result in unauthorized disclosure of sensitive data including user credentials, email addresses, and application configuration details. If the Joomla! database contains personally identifiable information (PII) or payment card data, this vulnerability poses regulatory compliance risks under GDPR, PCI-DSS, and similar frameworks. Additionally, extracted credentials could enable lateral movement into other systems or escalate to administrative compromise. Websites running this component should be considered at immediate risk of data exfiltration.

Affected systems

Only Joomla! installations with the User Bench component version 1.0 are affected. The vulnerability is unauthenticated and network-accessible, meaning any publicly exposed instance running this component can be attacked without prior system access. Organizations running other versions of User Bench or alternative Joomla! user management components are not directly impacted by this specific flaw.

Exploitability

This vulnerability has a high exploitability profile. It requires no authentication, no special privileges, and no user interaction. An attacker can craft a simple HTTP GET request and test the injection via automated scanning tools. The network attack vector means remote exploitation is trivial. No complex exploit development is necessary; basic SQL injection payloads (UNION SELECT, time-based blind techniques) will function. Given the age of this component and the simplicity of the attack, exploitation is considered straightforward.

Remediation

The immediate action is to disable or uninstall the User Bench component if it is not actively required. If the component is essential, the vendor should be contacted for a patched release. In the interim, apply web application firewall (WAF) rules to block SQL injection patterns in the userid parameter, and restrict access to the affected index.php endpoint to trusted IP ranges if possible. Review database access logs and consider resetting credentials for users who may have been exposed. For defense-in-depth, ensure database credentials used by Joomla! follow least-privilege principles and enable database query logging.

Patch guidance

Check the official User Bench component repository and Joomla! Extensions Directory for any available security updates. The vendor's release notes and security announcements should be consulted for patched versions. Apply any available patch immediately upon release. If the vendor has ceased support for this component, strongly consider migrating to an actively maintained Joomla! user management solution. Verify patch application by confirming the component version number in the component manifest and re-testing the injection parameter to ensure sanitization is in place.

Detection guidance

Monitor access logs for requests to index.php containing the option=com_userbench&view=detail&userid parameters with unusual or encoded characters, single quotes, SQL keywords (SELECT, UNION, OR, AND), or comment syntax (-- or /**/). Web application firewalls should alert on common SQL injection payloads. Database query logs should be reviewed for unexpected queries originating from the web application process. Security Information and Event Management (SIEM) systems can correlate HTTP 200 responses with suspicious query patterns. Conduct a filesystem scan to identify installations of the User Bench component and cross-reference with vulnerability scanning to confirm version 1.0 installations.

Why prioritize this

This vulnerability merits urgent attention due to its HIGH CVSS score (8.2), unauthenticated attack vector, and confidentiality impact. The ability to extract credentials and configuration data without authentication creates a direct pathway to further system compromise. Any organization running User Bench 1.0 on internet-facing Joomla! sites should treat this as a critical priority, as exploitation is trivial and the attacker gain is substantial. The lack of authentication or complexity makes this suitable for opportunistic automated attacks.

Risk score, explained

The CVSS 3.1 score of 8.2 reflects the following factors: Network-accessible attack vector (AV:N) with low attack complexity (AC:L) and no authentication required (PR:N) yield maximum exploitability. The confidentiality impact is high (C:H) because attackers can extract sensitive database information. Integrity impact is low (I:L), as the attack primarily enables reading rather than modification. Availability is not impacted (A:N). User interaction is not required (UI:N), and the scope is unchanged (S:U). This combination produces a HIGH severity classification. The score would be higher if the component allowed data modification or denial of service.

Frequently asked questions