CVE-2019-25751 Overview
CVE-2019-25751 is a SQL injection vulnerability in the Joomla extension J-ClassifiedsManager version 3.0.5. The flaw resides in the displayads component, which fails to sanitize user-supplied input passed through HTTP POST parameters. Unauthenticated attackers can inject arbitrary SQL by submitting crafted payloads in the categorySearch, adType, and citySearch parameters. Successful exploitation enables extraction of database contents including credentials, schema metadata, and version information. The weakness is categorized under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command).
Critical Impact
Remote, unauthenticated attackers can exfiltrate sensitive database contents — including user credentials and database schema — from any Joomla site running J-ClassifiedsManager 3.0.5.
Affected Products
- Joomla Component J-ClassifiedsManager 3.0.5
- Distributed via CMS Junkie
- Listed on the official Joomla Extensions Directory
Discovery Timeline
- 2026-06-19 - CVE-2019-25751 published to NVD
- 2026-06-23 - Last updated in NVD database
Technical Details for CVE-2019-25751
Vulnerability Analysis
The J-ClassifiedsManager displayads endpoint accepts POST parameters that are concatenated directly into SQL statements without parameterization or proper escaping. An attacker sending crafted input to categorySearch, adType, or citySearch breaks out of the intended query context and appends arbitrary SQL clauses. Because the endpoint is reachable without authentication, attack complexity remains low and prerequisites are minimal. Public exploitation details are documented in Exploit-DB entry 46231 and the VulnCheck advisory.
Root Cause
The root cause is missing input validation and absence of parameterized queries within the displayads request handler. User-controlled POST values flow directly into dynamically constructed SQL statements. The component does not enforce type checks, allow-lists, or prepared statement bindings on search parameters.
Attack Vector
The attack vector is network-based and requires no privileges or user interaction. An adversary issues a POST request to the J-ClassifiedsManager displayads endpoint with SQL metacharacters in the vulnerable fields. Union-based and error-based payloads can return database name, version, and table contents in HTTP responses. Refer to the Exploit-DB proof of concept for the documented payload structure.
Detection Methods for CVE-2019-25751
Indicators of Compromise
- POST requests to the Joomla displayads component containing SQL keywords such as UNION, SELECT, SLEEP, or INFORMATION_SCHEMA in the categorySearch, adType, or citySearch parameters.
- Unusual HTTP response sizes or 500-series errors originating from the J-ClassifiedsManager component endpoints.
- Web server access logs showing repeated requests from a single source iterating on payload variations.
Detection Strategies
- Deploy web application firewall (WAF) rules to flag SQL metacharacters and tautologies in POST bodies targeting the J-ClassifiedsManager endpoint.
- Enable Joomla query logging or MySQL general query logging and alert on queries containing concatenated user input from the affected parameters.
- Correlate web access logs with database error logs to identify failed injection attempts that surface as syntax errors.
Monitoring Recommendations
- Monitor outbound traffic from the web server for unusual data volume that could indicate database exfiltration.
- Track authentication anomalies on accounts whose credentials are stored in the affected database.
- Review Joomla extension inventory regularly to identify deployments of J-ClassifiedsManager 3.0.5.
How to Mitigate CVE-2019-25751
Immediate Actions Required
- Audit Joomla installations to determine whether J-ClassifiedsManager 3.0.5 is installed.
- Disable or unpublish the J-ClassifiedsManager component until a vendor-supplied fix is verified.
- Restrict access to the displayads endpoint via WAF or reverse proxy filtering until remediation is complete.
- Rotate database credentials and Joomla user passwords if exploitation is suspected.
Patch Information
No vendor patch URL is listed in the published advisory data. Administrators should consult the CMS Junkie resource hub and the Joomla Extensions Directory listing for the latest supported release and apply any available update that supersedes 3.0.5.
Workarounds
- Apply WAF signatures that block SQL injection patterns on POST parameters submitted to the J-ClassifiedsManager component.
- Enforce least-privilege database accounts so the Joomla database user cannot read tables outside its required scope.
- Place the Joomla site behind authentication or IP allow-listing while the component remains exposed.
# Example ModSecurity rule to block SQLi patterns on the vulnerable parameters
SecRule ARGS:categorySearch|ARGS:adType|ARGS:citySearch "@detectSQLi" \
"id:1002751,phase:2,deny,status:403,log,msg:'Possible CVE-2019-25751 J-ClassifiedsManager SQLi'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
