CVE-2017-20262: Joomla Ajax Quiz SQLi Vulnerability

CVE-2017-20262 Overview

CVE-2017-20262 is an SQL injection vulnerability [CWE-89] in the Joomla! AjaxQuiz component version 1.8. The flaw resides in the handling of the cid parameter when the component processes GET requests to index.php with option=com_ajaxquiz and view=ajaxquiz. Unauthenticated remote attackers can inject arbitrary SQL statements through this parameter. Successful exploitation lets attackers enumerate table names, extract column structures, and read sensitive database contents.

Critical Impact
Unauthenticated remote attackers can execute arbitrary SQL queries against the backend database and exfiltrate stored data from any Joomla! site running the vulnerable AjaxQuiz 1.8 extension.

Affected Products

Joomla! Extension: AjaxQuiz version 1.8
Joomla! sites with the com_ajaxquiz component installed and enabled
Vendor: Webkul

Discovery Timeline

2026-06-19 - CVE-2017-20262 published to NVD
2026-06-23 - Last updated in NVD database

Technical Details for CVE-2017-20262

Vulnerability Analysis

The AjaxQuiz component fails to sanitize or parameterize input supplied through the cid request parameter. When a request is sent to index.php?option=com_ajaxquiz&view=ajaxquiz&cid=<payload>, the component concatenates the attacker-controlled value directly into a SQL query executed against the Joomla! database. This SQL injection vector is reachable without authentication, expanding the exposure to any internet-facing instance.

Attackers can leverage standard UNION SELECT-based and boolean blind techniques to enumerate the information_schema tables, dump credential hashes from #__users, and read session tokens. Because Joomla! databases frequently host content for multiple extensions, the impact extends beyond the quiz module itself.

The EPSS model estimates a probability of 0.334% with a percentile of 25.19, indicating modest but non-zero exploitation likelihood. A public proof of concept exists as Exploit-DB #42532, and the VulnCheck Advisory: AjaxQuiz SQL Injection documents the issue.

Root Cause

The root cause is improper neutralization of special elements used in an SQL command. The component reads the cid parameter from the HTTP request and embeds it in a query string without parameter binding, type casting, or escaping through Joomla!'s JDatabaseQuery API.

Attack Vector

The attack vector is network-based. An attacker crafts a GET request such as index.php?option=com_ajaxquiz&view=ajaxquiz&cid=1 UNION SELECT ... against any reachable Joomla! site hosting the vulnerable extension. No privileges, user interaction, or prior reconnaissance beyond identifying the component are required. See the VulnCheck Advisory: AjaxQuiz SQL Injection for the technical request structure.

Detection Methods for CVE-2017-20262

Indicators of Compromise

Web server access logs containing option=com_ajaxquiz together with view=ajaxquiz and SQL keywords such as UNION, SELECT, SLEEP, INFORMATION_SCHEMA, or 0x in the cid parameter.
Unexpected database errors logged by Joomla! referencing the #__ajaxquiz tables or malformed cid values.
Outbound traffic from the web server to attacker-controlled hosts immediately following requests to the com_ajaxquiz endpoint.

Detection Strategies

Deploy Web Application Firewall (WAF) signatures that flag SQL metacharacters in the cid query parameter for the com_ajaxquiz route.
Hunt historical web logs for requests matching the pattern index.php?option=com_ajaxquiz&view=ajaxquiz&cid= followed by encoded SQL syntax.
Correlate web request anomalies with database audit logs to identify queries against information_schema or the #__users table originating from the Joomla! application user.

Monitoring Recommendations

Enable verbose query logging on the database server during incident review to capture injected payloads executed by the Joomla! account.
Alert on bursts of HTTP 500 responses from index.php paths containing com_ajaxquiz, as blind SQL injection commonly produces error spikes.
Track installed Joomla! extensions through configuration management and flag instances where AjaxQuiz 1.8 remains present.

How to Mitigate CVE-2017-20262

Immediate Actions Required

Disable or uninstall the AjaxQuiz 1.8 extension through the Joomla! Extension Manager until a vendor fix is verified.
Block external requests containing option=com_ajaxquiz at the WAF or reverse proxy if the component is not business-critical.
Rotate Joomla! administrator credentials and database account passwords if logs indicate prior exploitation attempts.

Patch Information

No vendor patch is referenced in the NVD record or vendor resources at the time of publication. Operators should consult the Joomla Extension: AjaxQuiz listing and the Webkul Home Page for any updated builds, and remove the extension if no fixed release is available.

Workarounds

Restrict access to the com_ajaxquiz endpoint via .htaccess or NGINX location rules until the component is removed or replaced.
Apply WAF rules that enforce numeric-only validation on the cid parameter for any request targeting index.php with option=com_ajaxquiz.
Run Joomla! under a database account with the minimum privileges required, removing FILE, CREATE, and write access to tables outside its scope to limit post-exploitation impact.

bash

# Example NGINX rule blocking the vulnerable endpoint
location = /index.php {
    if ($args ~* "option=com_ajaxquiz") {
        return 403;
    }
}