CVE-2017-20245: Wow Viral Signups Plugin SQLi Vulnerability

CVE-2017-20245 Overview

CVE-2017-20245 is an SQL injection vulnerability in version 2.1 of the Wow Viral Signups 2 WordPress plugin (also known as mwp-viral-signup). The flaw resides in the handling of the idsignup POST parameter sent to admin-ajax.php, which is concatenated into a SQL query without proper sanitization or parameterization. Unauthenticated remote attackers can submit crafted payloads to extract arbitrary data from the WordPress database, including user credentials, session tokens, and configuration secrets. The weakness is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command.

Critical Impact

Unauthenticated attackers can read arbitrary data from the WordPress database — including administrator password hashes — by sending a single crafted POST request to the AJAX endpoint.

Affected Products

• Wow Viral Signups 2 WordPress plugin version 2.1
• WordPress installations using the mwp-viral-signup plugin
• Sites exposing admin-ajax.php to unauthenticated traffic with the plugin enabled

Discovery Timeline

• 2026-06-09 - CVE-2017-20245 published to NVD
• 2026-06-09 - Last updated in NVD database

Technical Details for CVE-2017-20245

Vulnerability Analysis

The vulnerability stems from the plugin's AJAX handler accepting the idsignup parameter and embedding it directly into a SQL statement. Because the value is neither cast to an integer nor passed through wpdb::prepare(), an attacker controls the structure of the resulting query. The handler is registered for both authenticated and unauthenticated visitors, so exploitation requires no WordPress account or session.

The impact aligns with a classic Boolean-based or UNION-based extraction primitive against the WordPress database. Attackers can read from wp_users, wp_usermeta, and wp_options, exfiltrating password hashes, secret keys, and API tokens. Recovered administrator hashes can be cracked offline or used in pass-the-hash style follow-up attacks against connected services.

Detailed technical analysis is published in the VulnCheck Advisory on SQL Injection and a working proof of concept is available at Exploit-DB #41921.

Root Cause

The root cause is missing input validation and the absence of prepared statements. The idsignup value, expected to be a numeric record identifier, is concatenated into the SQL string without type enforcement. WordPress provides wpdb::prepare() and absint() specifically to prevent this pattern, but the plugin uses neither for this code path.

Attack Vector

Exploitation occurs over the network against the WordPress admin-ajax.php endpoint. The attacker issues a POST request specifying the plugin's AJAX action and supplies a malicious payload in the idsignup field. Standard SQLi techniques — UNION SELECT, time-based blind, and error-based extraction — all apply because the injection point sits inside a SELECT statement and no authentication or nonce check is performed.

No verified sanitized exploit code is reproduced here. Refer to the Exploit-DB #41921 entry for the original proof of concept.

Detection Methods for CVE-2017-20245

Indicators of Compromise

• POST requests to /wp-admin/admin-ajax.php containing the parameter idsignup with non-numeric content such as SQL keywords (UNION, SELECT, SLEEP, BENCHMARK).
• Web server access logs showing repeated admin-ajax.php requests from a single source with varying idsignup values, indicating automated extraction.
• Database error entries referencing the plugin's SQL statements or unexpected wp_users reads originating from the web user.

Detection Strategies

• Deploy a WAF rule that inspects POST bodies to admin-ajax.php and blocks idsignup values that are not strictly integer.
• Hunt historical proxy and access logs for the idsignup parameter combined with URL-encoded SQL metacharacters (%27, %20UNION%20, %20OR%201%3D1).
• Enable WordPress query logging or MySQL general query logs on test environments to baseline legitimate plugin traffic, then alert on deviations.

Monitoring Recommendations

• Monitor outbound responses from admin-ajax.php for unusually large payload sizes consistent with data extraction.
• Alert on authentication anomalies such as administrator logins from new IPs following any suspicious admin-ajax.php activity, since stolen hashes may have been cracked.
• Track plugin inventory across WordPress estates and flag any host still running mwp-viral-signup version 2.1.

How to Mitigate CVE-2017-20245

Immediate Actions Required

• Deactivate and uninstall the Wow Viral Signups 2 plugin from all WordPress sites until a confirmed fixed version is verified.
• Rotate all WordPress administrator passwords, wp-config.php secret keys, and any API tokens stored in wp_options on affected sites.
• Review database audit logs and access logs for the past retention window for evidence of idsignup exploitation attempts.

Patch Information

No confirmed vendor patch URL is listed in the available references. Consult the WordPress Plugin Information page and the Wow Company Homepage for current release status. If the plugin remains unmaintained, permanent removal is the recommended remediation.

Workarounds

• Block requests to admin-ajax.php containing the idsignup parameter at the WAF or reverse proxy until the plugin is removed.
• Restrict access to wp-admin/admin-ajax.php from untrusted networks where business requirements permit.
• Enforce a least-privilege MySQL user for WordPress so that the web account cannot read tables outside the WordPress schema.

# Example ModSecurity rule to block non-numeric idsignup values
SecRule REQUEST_URI "@endsWith /wp-admin/admin-ajax.php" \
  "chain,phase:2,deny,status:403,id:1020245,\
   msg:'CVE-2017-20245: Wow Viral Signups idsignup SQLi attempt'"
  SecRule ARGS:idsignup "!@rx ^[0-9]+$"