CVE-2018-25434: WP AutoSuggest 0.24 Unauthenticated SQL Injection Vulnerability

Technical summary

The vulnerability exists in WP AutoSuggest 0.24's handling of the wpas_keys GET parameter in autosuggest.php. The plugin fails to properly sanitize or parameterize this input before constructing and executing SQL queries, allowing attackers to inject arbitrary SQL syntax. The attack vector is network-accessible and requires no authentication or user interaction. An attacker can craft requests containing SQL metacharacters or stacked queries to extract, modify, or delete data from the WordPress database. The vulnerability maps to CWE-89 (SQL Injection), a well-understood and easily exploitable class of defect.

Business impact

Successful exploitation compromises the confidentiality of your WordPress installation. Attackers gain direct read access to your database, potentially exposing customer data, email addresses, post metadata, plugin configurations, and user credentials stored in plaintext or with weak hashing. While the CVSS vector suggests limited impact on integrity and no impact on availability, in practice attackers who can read your database can often pivot to modify configuration, inject backdoors, or establish persistence. For organizations running WP AutoSuggest 0.24, this represents a data breach risk that may trigger regulatory notification obligations under GDPR, CCPA, and similar regimes.

Affected systems

WordPress installations using WP AutoSuggest plugin version 0.24 are directly affected. The vulnerability is unauthenticated and remotely exploitable, meaning any internet-facing WordPress site running this specific version is at immediate risk. Multisite WordPress deployments are equally vulnerable. The issue does not appear to affect other WordPress plugins or WP AutoSuggest versions beyond 0.24, though you should verify the actual version lineage and whether any intermediate releases were affected by consulting the vendor advisory.

Exploitability

This vulnerability is highly exploitable. It requires no authentication, no special configuration, and no user interaction. An attacker needs only to craft a simple HTTP GET request with a malicious wpas_keys parameter. The SQL injection technique is straightforward to execute using widely available tools and manual methods. No complex timing, race conditions, or sophisticated understanding of WordPress internals is required. The attack can be automated and scaled across multiple targets. The barrier to entry is very low, making this vulnerability attractive to both opportunistic scanners and targeted attackers.

Remediation

Immediately deactivate and remove WP AutoSuggest 0.24 from all WordPress installations. Check your plugins directory and WordPress admin dashboard for this plugin. If you rely on the autosuggest functionality for user experience, evaluate alternative plugins that are actively maintained and have undergone security review. Before reactivating any plugin, confirm it has been updated to a patched version or replaced entirely. As a longer-term control, ensure your WordPress installation enforces automatic plugin updates or has a strict change-control process that prevents the installation of unmaintained or vulnerable plugins.

Patch guidance

Verify the latest WP AutoSuggest version available from the WordPress plugin repository or vendor website. The current guidance is to discontinue use of version 0.24 entirely. If a patched version is available, test it in a staging environment before deployment to production. If no patch exists or the plugin is abandoned, switch to an alternative autosuggest solution. When deploying any replacement, configure it to use parameterized queries or prepared statements to prevent SQL injection, and apply the principle of least privilege to the database user account the plugin uses.

Detection guidance

Monitor web server access logs for GET requests to autosuggest.php containing suspicious parameters, especially those with SQL keywords (SELECT, UNION, OR, AND, comments like -- or /*), SQL metacharacters (single quotes, semicolons), or hex-encoded payloads. Deploy a Web Application Firewall (WAF) rule to block requests to autosuggest.php from untrusted sources or inspect them for SQL injection patterns. Check your WordPress error logs and database logs for unusual query activity or errors. Use a security scanner or manual code review to confirm WP AutoSuggest 0.24 is not present in your environment. If you have historical logs, search for exploitation attempts using patterns like wpas_keys=.*(%27|%22|--|/\*|union|select).

Why prioritize this

This vulnerability warrants immediate action because it combines high exploitability, network accessibility, no authentication requirement, and direct database read access. The CVSS 8.2 HIGH score reflects the severity accurately. Although it is not yet listed on the CISA KEV catalog, the lack of KEV status does not reduce its risk—it simply indicates either low observed exploitation in the wild at the time of publication or a recent disclosure. For any organization running WP AutoSuggest 0.24, treating this as P1/critical is justified. Delay in remediation directly increases the window for data exfiltration.

Risk score, explained

The CVSS 3.1 score of 8.2 (HIGH) is assigned because: attack vector is network (AV:N), attack complexity is low (AC:L), no privileges required (PR:N), no user interaction required (UI:N), the scope is unchanged (S:U), and there is high confidentiality impact (C:H) due to unauthenticated database read access. The integrity impact is rated low (I:L) because while an attacker can theoretically craft queries to modify data, the primary vulnerability is read-based; availability impact is none (A:N) because queries alone do not cause denial of service. The score reflects a serious vulnerability that enables data theft but does not by itself enable system-wide destruction.

Frequently asked questions