CVE-2025-23912 Overview
CVE-2025-23912 is a blind SQL injection vulnerability [CWE-89] in the Philipp Speck WordPress Custom Sidebar plugin (wordpress-custom-sidebar). The flaw affects all versions up to and including 2.3. Authenticated attackers with low privileges can inject malicious SQL through unsanitized input parameters processed by the plugin. The injection is blind, meaning attackers infer results from timing or boolean-based responses rather than direct output. Successful exploitation exposes WordPress database contents, including user credentials, session tokens, and arbitrary post data stored in wp_users and other core tables.
Critical Impact
A low-privileged authenticated user can extract sensitive database contents from WordPress installations running the vulnerable plugin, with scope change extending impact beyond the plugin context.
Affected Products
- Philipp Speck WordPress Custom Sidebar plugin
- All versions from n/a through <= 2.3
- WordPress installations with the wordpress-custom-sidebar plugin enabled
Discovery Timeline
- 2025-01-16 - CVE-2025-23912 published to NVD
- 2026-04-23 - Last updated in NVD database
Technical Details for CVE-2025-23912
Vulnerability Analysis
The vulnerability stems from improper neutralization of special elements used in SQL commands within the WordPress Custom Sidebar plugin. The plugin processes user-supplied input and concatenates it into SQL queries without adequate sanitization or parameterized statements. WordPress provides $wpdb->prepare() for safe parameter binding, but the affected code paths bypass this protection. Attackers craft payloads containing SQL metacharacters that alter query logic at execution time. Because the injection is blind, exploitation relies on conditional response differences or time-based payloads using functions such as SLEEP() or BENCHMARK(). The attack requires only low-level authentication, lowering the bar for exploitation in multi-user WordPress environments where subscriber or contributor accounts are common.
Root Cause
The root cause is unsafe handling of request parameters that are passed directly into SQL statements without using prepared statements or escaping through esc_sql() or $wpdb->prepare(). WordPress plugins commonly introduce this class of flaw when developers build dynamic queries using string concatenation. The blind nature indicates that query output is not reflected in the HTTP response, but errors or timing variations leak data one bit at a time.
Attack Vector
An authenticated attacker submits crafted HTTP requests containing SQL injection payloads to plugin endpoints. The attacker uses conditional logic such as AND IF(SUBSTRING(user_pass,1,1)='a',SLEEP(5),0) against the WordPress users table to extract credentials character by character. The scope change indicates the injection affects data outside the vulnerable component, allowing access to the entire WordPress database including authentication secrets and personally identifiable information stored across plugins.
No public proof-of-concept code is verified for this CVE. Refer to the Patchstack Vulnerability Report for additional technical details.
Detection Methods for CVE-2025-23912
Indicators of Compromise
- HTTP requests to WordPress Custom Sidebar plugin endpoints containing SQL metacharacters such as ', --, UNION, SLEEP(, or BENCHMARK(.
- Unusual response time variations on plugin endpoints indicating time-based blind injection attempts.
- Database query logs showing malformed or unexpected SELECT statements originating from plugin code paths.
- Authenticated session activity from low-privilege accounts performing repeated parameterized requests to the same plugin endpoint.
Detection Strategies
- Deploy web application firewall (WAF) rules to flag SQL injection signatures targeting WordPress plugin endpoints.
- Enable WordPress query monitoring plugins or MySQL general query logging to identify suspicious query patterns.
- Correlate authenticated user activity with response time anomalies to surface blind injection probes.
- Monitor for spikes in 500-series HTTP errors that may indicate failed injection attempts.
Monitoring Recommendations
- Aggregate WordPress access logs and MySQL logs into a centralized analytics platform for cross-source correlation.
- Alert on repeated requests from a single authenticated session that exhibit SLEEP() or BENCHMARK() keywords in parameters.
- Track plugin version inventory across hosted WordPress sites to identify exposed installations.
How to Mitigate CVE-2025-23912
Immediate Actions Required
- Disable the WordPress Custom Sidebar plugin until a patched version above 2.3 is available and verified.
- Audit WordPress user accounts and remove unnecessary low-privilege accounts that could be leveraged for exploitation.
- Rotate WordPress administrator passwords and database credentials if compromise is suspected.
- Review database access logs for evidence of data exfiltration tied to the plugin's endpoints.
Patch Information
At the time of publication, no fixed version above 2.3 is referenced in the advisory. Monitor the Patchstack Vulnerability Report and the WordPress plugin repository for an official update.
Workarounds
- Remove the wordpress-custom-sidebar plugin directory from wp-content/plugins/ if a patch is unavailable.
- Deploy WAF signatures that block SQL injection payloads targeting the plugin's request parameters.
- Restrict authenticated access to the plugin's admin endpoints using server-level access controls or IP allowlisting.
- Apply the principle of least privilege to the WordPress database user, limiting SELECT access only to required tables.
# Disable the vulnerable plugin via WP-CLI
wp plugin deactivate wordpress-custom-sidebar
wp plugin delete wordpress-custom-sidebar
# Verify removal
wp plugin list | grep wordpress-custom-sidebar
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
