CVE-2025-30622: PostMash Custom SQL Injection Vulnerability

CVE-2025-30622 Overview

CVE-2025-30622 is a SQL Injection vulnerability in the torsteino PostMash (postmash-custom) WordPress plugin. The flaw affects all versions up to and including 1.0.3. Attackers can inject malicious SQL statements through unsanitized input parameters processed by the plugin.

The vulnerability stems from improper neutralization of special elements used in SQL commands [CWE-89]. Exploitation requires no authentication and no user interaction, and it occurs over the network. Successful exploitation can expose sensitive WordPress database contents and affect availability of the underlying site.

Critical Impact
Unauthenticated remote attackers can inject arbitrary SQL queries against WordPress sites running PostMash <= 1.0.3, leading to confidentiality exposure and partial availability impact.

Affected Products

torsteino PostMash (postmash-custom) WordPress plugin
All versions from initial release through 1.0.3
WordPress sites with the vulnerable plugin installed and activated

Discovery Timeline

2025-04-01 - CVE-2025-30622 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2025-30622

Vulnerability Analysis

The PostMash plugin fails to properly neutralize special characters in SQL commands constructed from user-supplied input. The plugin reorders WordPress posts and passes parameters into database queries without adequate sanitization or use of prepared statements.

Attackers craft requests containing SQL metacharacters such as single quotes, comments, and UNION clauses. These payloads alter the structure of backend SQL queries executed by the WordPress database layer ($wpdb). The scope is marked as changed, indicating the injected query can affect resources beyond the vulnerable component's security boundary.

The attack requires no privileges and no user interaction. This combination places the flaw among the most accessible categories of WordPress plugin vulnerabilities.

Root Cause

The root cause is direct concatenation of untrusted input into SQL statements without parameter binding. WordPress provides safe query mechanisms through $wpdb->prepare(), but the plugin's ordering or query-handling logic bypasses these safeguards. CWE-89 classifies this as Improper Neutralization of Special Elements used in an SQL Command.

Attack Vector

The attack vector is network-based via HTTP(S) requests to the WordPress site hosting the plugin. An unauthenticated attacker sends crafted parameters to plugin endpoints that reach the vulnerable query builder. Because no authentication is required, mass scanning and automated exploitation against exposed WordPress installations are feasible.

Technical details and proof-of-concept information are referenced in the Patchstack SQL Injection Vulnerability advisory.

Detection Methods for CVE-2025-30622

Indicators of Compromise

HTTP requests to PostMash plugin endpoints containing SQL metacharacters such as ', --, UNION SELECT, SLEEP(, or INFORMATION_SCHEMA.
Unexpected outbound database errors logged by WordPress or PHP referencing the wp_posts table or plugin query handlers.
Anomalous read patterns against the WordPress database from the web application user, including bulk reads of wp_users or wp_options.

Detection Strategies

Inspect web server access logs for query strings targeting postmash-custom plugin paths combined with SQL injection signatures.
Deploy or tune web application firewall (WAF) rules that flag SQLi payloads against WordPress plugin endpoints.
Correlate WordPress debug logs and MySQL slow query logs for malformed or unusually long queries originating from plugin code paths.

Monitoring Recommendations

Monitor authentication-free plugin endpoints for spikes in request volume from single source IPs.
Alert on responses containing database error strings such as You have an error in your SQL syntax returned to anonymous clients.
Track changes to administrative accounts, session tokens, and wp_options rows that may indicate post-exploitation database tampering.

How to Mitigate CVE-2025-30622

Immediate Actions Required

Identify all WordPress sites running the PostMash (postmash-custom) plugin and confirm the installed version.
Deactivate and remove the plugin on any installation running version 1.0.3 or earlier until a fixed release is verified.
Rotate WordPress administrator credentials, secret keys in wp-config.php, and any database credentials that may have been exposed.

Patch Information

At the time of publication, no fixed version has been confirmed in the referenced advisory. Administrators should consult the Patchstack advisory for PostMash for vendor updates and apply any released patch promptly. Until a verified patch exists, removal of the plugin is the recommended action.

Workarounds

Block requests to PostMash plugin endpoints at the WAF or reverse proxy layer using virtual patching rules from providers such as Patchstack or Wordfence.
Restrict access to the WordPress admin and plugin URLs by source IP where feasible.
Apply the principle of least privilege to the MySQL account used by WordPress, limiting it to only the databases and operations required.

bash

# Example: virtual patching rule pattern for an Nginx/ModSecurity deployment
# Block requests targeting the vulnerable plugin containing SQLi indicators
SecRule REQUEST_URI "@contains /wp-content/plugins/postmash-custom/" \
    "id:1009030622,phase:2,deny,status:403,\
    msg:'CVE-2025-30622 PostMash SQLi attempt',\
    chain"
    SecRule ARGS "@rx (?i)(union(\s|/\*.*\*/)+select|sleep\(|information_schema|--\s|';)" \
        "t:none,t:urlDecodeUni"