CVE-2017-20256: Joomla Survey Force Deluxe SQLi Flaw

CVE-2017-20256 Overview

CVE-2017-20256 is an SQL injection vulnerability [CWE-89] in the Joomla extension Survey Force Deluxe version 3.2.4 from Joomplace. The flaw resides in the invite parameter handling, where user-supplied input flows into a SQL query without sanitization. Unauthenticated remote attackers can send crafted GET requests to extract sensitive database contents, including credentials and survey data. The vulnerability requires no privileges and no user interaction, making it trivial to exploit against any Joomla site running the affected extension.

Critical Impact

Unauthenticated attackers can execute arbitrary SQL queries through the invite parameter, exposing the entire backend database of affected Joomla installations.

Affected Products

• Joomplace Survey Force Deluxe 3.2.4 (Joomla extension)
• Joomla installations with the Survey Force Deluxe component installed
• Earlier 3.x versions of Survey Force Deluxe may also be affected

Discovery Timeline

• 2026-06-19 - CVE-2017-20256 published to NVD
• 2026-06-23 - Last updated in NVD database

Technical Details for CVE-2017-20256

Vulnerability Analysis

The vulnerability resides in the Survey Force Deluxe Joomla component, which exposes survey invitation functionality through HTTP GET requests. The invite parameter is passed directly into a backend SQL query without parameterization or input sanitization. An attacker can append SQL syntax such as UNION SELECT statements to read arbitrary data from connected tables.

Successful exploitation allows extraction of Joomla user records, including password hashes stored in the #__users table, along with session tokens and configuration values. Because Joomla typically shares one database across the CMS and all extensions, the breach extends well beyond the survey component. The vulnerability is classified under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command). Public exploit code has been documented in Exploit-DB entry 42606.

Root Cause

The component fails to apply prepared statements or input filtering to the invite query parameter before concatenating it into a SQL statement. Joomla provides safe database abstraction methods through JDatabaseDriver, but Survey Force Deluxe 3.2.4 bypasses these protections for this code path.

Attack Vector

Exploitation requires only an HTTP client capable of issuing GET requests to the vulnerable Joomla endpoint. The attacker supplies a malicious payload in the invite query parameter, for example using boolean-based or UNION-based SQL injection techniques. Network access to the target site is sufficient — no authentication, session, or user interaction is needed. Refer to the VulnCheck Joomla SQL Injection Advisory and Exploit-DB #42606 for technical proof-of-concept details.

Detection Methods for CVE-2017-20256

Indicators of Compromise

• GET requests to Joomla URLs containing option=com_surveyforce combined with an invite parameter holding SQL keywords such as UNION, SELECT, SLEEP, or --.
• Web server access logs showing abnormally long invite parameter values or URL-encoded SQL syntax (%27, %20UNION%20).
• Database error messages or unusually large response sizes returned from the survey component.
• Outbound connections or new administrator accounts created shortly after suspicious requests to the survey endpoint.

Detection Strategies

• Inspect web application firewall and reverse proxy logs for SQL injection signatures targeting the invite parameter on com_surveyforce URLs.
• Correlate authentication anomalies in Joomla, such as logins from new IPs using existing admin accounts, with prior requests to the vulnerable component.
• Enable Joomla query logging or database audit logging to capture unexpected UNION or schema-introspection queries against the #__users table.

Monitoring Recommendations

• Monitor HTTP request rates and parameter entropy on Joomla extension endpoints to flag automated SQLi scanners.
• Alert on database queries originating from the web application user that reference information_schema, #__users, or #__session outside of normal Joomla operations.
• Track file integrity on the Joomla webroot to detect webshells or modified administrator templates following suspected exploitation.

How to Mitigate CVE-2017-20256

Immediate Actions Required

• Disable or uninstall the Survey Force Deluxe component from Joomla Administrator until a fixed version is confirmed available from Joomplace.
• Block requests to com_surveyforce URLs at the web application firewall, or restrict access to trusted IP ranges where the extension is required.
• Rotate Joomla administrator passwords and invalidate active sessions, assuming the user table may have been exfiltrated.
• Review database logs and Joomla audit history for unauthorized account creation or privilege changes.

Patch Information

No vendor patch is referenced in the NVD entry for CVE-2017-20256. Administrators should contact Joomplace through the Joomplace Official Website and check the Joomla Extensions Directory listing for an updated release. Until a patched build is verified, removing the extension is the only reliable remediation.

Workarounds

• Deploy a web application firewall rule that drops GET requests where the invite parameter contains SQL metacharacters or keywords (', ", UNION, SELECT, --, ;).
• Restrict the database user used by Joomla to least privilege, removing rights to information_schema and limiting access to only the tables required by the CMS.
• Place the Joomla site behind authentication or IP allowlisting if the survey functionality is only used internally.

# Example ModSecurity rule to block SQLi in the invite parameter
SecRule ARGS:invite "@detectSQLi" \
    "id:1020256,phase:2,deny,status:403,\
    msg:'CVE-2017-20256 Survey Force Deluxe SQLi attempt',\
    logdata:'Matched value: %{MATCHED_VAR}'"