CVE-2017-20262: SQL Injection in Joomla Ajax Quiz Component v1.8

Technical summary

CVE-2017-20262 is a classic SQL injection vulnerability (CWE-89) in the Joomla Ajax Quiz component v1.8. The flaw exists in the handling of the 'cid' parameter when processing requests to index.php with option=com_ajaxquiz and view=ajaxquiz. Insufficient input validation and sanitization allow attackers to append SQL metacharacters and commands, which the application then executes against the database backend. The vulnerability is unauthenticated, meaning no valid credentials are required to trigger it. While the primary impact is confidentiality (database enumeration and data exfiltration), limited write capabilities may also be present depending on database permissions. The CVSS 3.1 score of 8.2 reflects high network accessibility, low attack complexity, and significant confidentiality impact.

Business impact

A successful exploitation of this SQL injection could expose your Joomla installation's entire database to attackers. Potential stolen data includes user account information, passwords (if stored insecurely), email addresses, and any custom data stored in Joomla tables. For organizations using Joomla for e-commerce, membership, or customer relationship management, this could lead to regulatory compliance violations (GDPR, CCPA), reputational damage, and loss of customer trust. The unauthenticated nature of the attack means threat actors can probe and extract data without triggering standard login-based detection mechanisms.

Affected systems

Joomla installations with the Ajax Quiz component version 1.8 are directly vulnerable. Any website running this specific component version is at risk if the site is internet-facing and the component is enabled. Custom Joomla deployments that integrate or extend this component may also be affected, depending on how modifications handle the 'cid' parameter. Organizations should inventory their Joomla instances and identify which ones have Ajax Quiz installed and active.

Exploitability

This vulnerability is highly exploitable. No authentication is required, the attack is trivial to execute (a simple HTTP GET request with injected SQL), network access is all that is needed, and no user interaction is required. Automated tools and publicly available proof-of-concept code can scan for vulnerable instances. The likelihood of exploitation in the wild is substantial, especially for internet-exposed Joomla sites that have not been regularly patched. Attackers need only basic SQL knowledge to craft effective payloads.

Remediation

Immediately update the Ajax Quiz component to a patched version released by the Joomla maintainers. Verify the specific patched version against the component's official security advisories and release notes. If no patch is available or the component is no longer maintained, consider disabling or removing the component entirely. Additionally, review your database access controls to ensure the web server process runs with least-privilege database credentials (no unnecessary DROP, ALTER, or administrative permissions).

Patch guidance

Contact the Joomla Ajax Quiz component maintainer or check the Joomla Extension Directory for an updated version of the component. Apply the update only after testing in a non-production environment to ensure compatibility with your Joomla version and other installed extensions. If the component has reached end-of-life or no patch is forthcoming, plan a replacement with a maintained alternative or remove the functionality entirely. Document the patching date and version applied for audit purposes.

Detection guidance

Monitor web server access logs for suspicious patterns in requests to index.php that contain the parameters option=com_ajaxquiz, view=ajaxquiz, and cid with SQL keywords (SELECT, UNION, OR, AND, EXEC, etc.). Deploy a Web Application Firewall (WAF) with SQL injection detection rules to block or alert on malicious payloads targeting this parameter. Enable database query logging and monitor for unexpected queries or errors that might indicate injection attempts. Conduct a forensic review of database access logs and table queries from the period before patching to identify potential breaches.

Why prioritize this

This vulnerability warrants immediate patching due to its HIGH CVSS score (8.2), unauthenticated exploitability, and direct path to sensitive data exposure. The attack surface is wide (any internet-exposed Joomla instance with the component), the technical barrier to exploitation is low, and the business impact is severe. Unlike many vulnerabilities that require user interaction or specific configurations, this flaw is trivial to exploit and can be weaponized at scale.

Risk score, explained

The CVSS 3.1 score of 8.2 (HIGH) reflects: (1) Network-based attack vector—no local access needed; (2) Low attack complexity—no special conditions or privileges required; (3) No privilege escalation required; (4) Unauthenticated access; (5) High confidentiality impact—full database disclosure is possible; (6) Limited integrity impact—depending on database permissions, some write operations may succeed; (7) No availability impact in the base scenario. The score appropriately emphasizes the ease and reach of the attack balanced against the confirmed high-impact data exposure outcome.

Frequently asked questions