CVE-2019-25751: Joomla J-ClassifiedsManager SQL Injection Vulnerability

Technical summary

CVE-2019-25751 is an unauthenticated SQL injection (CWE-89) in the J-ClassifiedsManager 3.0.5 component's displayads functionality. The vulnerability exists in POST parameter handling, specifically within the categorySearch, adType, and citySearch parameters, which are not properly sanitized before being passed to SQL queries. An attacker can construct malicious SQL payloads that execute arbitrary queries against the underlying database, enabling data exfiltration of sensitive schema and user information.

Business impact

Organizations running vulnerable versions of this Joomla component face direct risk of unauthorized database access and information disclosure. Customer credentials, database schema details, and system configuration data could be extracted by attackers, leading to downstream compromise. The combination of no authentication requirement and high confidentiality impact creates significant compliance and reputational risk, particularly for sites handling customer personal data.

Affected systems

The vulnerability specifically affects Joomla Component J-ClassifiedsManager version 3.0.5. The displayads module and its POST parameter processing are the entry points. Any publicly accessible Joomla installation running this exact component version is vulnerable; verify your installed version through the Joomla administrator panel or by checking the component directory on your server.

Exploitability

This vulnerability has a CVSS 3.1 score of 8.2 (HIGH) with a network-based attack vector, low complexity, and no authentication or user interaction required. The attack surface is the displayads component's POST handlers. While no public exploit code is documented in KEV, the straightforward nature of SQL injection in web parameters means exploitation difficulty is low for someone with basic SQL knowledge. The lack of CISA KEV designation does not imply lower risk—it reflects current exploitation tracking status only.

Remediation

Immediately identify and inventory all Joomla installations using J-ClassifiedsManager 3.0.5. Contact the component vendor for a patched version or disable the component if no patch is available. Verify the patch version against the vendor's official advisory before deployment. As an interim control, implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns in the displayads parameters, and restrict component access via network segmentation if possible.

Patch guidance

Obtain the latest patched version of J-ClassifiedsManager from the official vendor. Before applying any patch, test it in a non-production environment to ensure compatibility with your Joomla version and other installed extensions. Refer to the vendor's official security advisory for the specific patched version number, installation steps, and any breaking changes. Back up your database and configuration files prior to patching.

Detection guidance

Monitor HTTP POST requests to the displayads component for SQL metacharacters (semicolons, quotes, SQL keywords like UNION, SELECT, DROP) in the categorySearch, adType, and citySearch parameters. Enable Joomla's database query logging if available, and search logs for unexpected SQL commands or error messages indicating injection attempts. WAF logs should capture blocked SQL injection attempts. Check database access logs for unusual query patterns originating from web application processes.

Why prioritize this

This vulnerability merits immediate attention due to its HIGH CVSS score (8.2), unauthenticated exploitation path, and direct impact to confidentiality. The ability to extract database credentials and schema information creates a beachhead for further compromise. Organizations should prioritize patching or disabling J-ClassifiedsManager 3.0.5 before addressing lower-severity items.

Risk score, explained

The CVSS 3.1 score of 8.2 reflects the vulnerability's network accessibility, absence of authentication barriers, and high confidentiality impact balanced against limited integrity impact and no availability impact. The score emphasizes that an attacker can easily reach the vulnerability and extract sensitive data, but cannot directly modify or delete data or cause denial of service through the SQL injection itself. This is a high-risk posture for any organization with exposed Joomla instances.

Frequently asked questions