CVE-2024-43116: Simple Local Avatars CSRF Vulnerability

CVE-2024-43116 Overview

CVE-2024-43116 is a Cross-Site Request Forgery (CSRF) vulnerability [CWE-352] in the 10up Simple Local Avatars plugin for WordPress. The flaw affects all plugin versions up to and including 2.7.10. An attacker can craft a malicious web page that, when visited by an authenticated WordPress user, causes the user's browser to issue unauthorized requests to the vulnerable plugin endpoints. Successful exploitation can compromise confidentiality, integrity, and availability of the affected site. The vulnerability requires user interaction such as clicking a crafted link or visiting an attacker-controlled page while authenticated.

Critical Impact

An attacker can hijack authenticated sessions to perform unauthorized state-changing actions through the Simple Local Avatars plugin, leading to potential site compromise.

Affected Products

• 10up Simple Local Avatars plugin for WordPress
• All versions from initial release through 2.7.10
• WordPress sites running the plugin with authenticated administrator or editor users

Discovery Timeline

• 2024-08-26 - CVE-2024-43116 published to the National Vulnerability Database
• 2024-09-18 - Last updated in NVD database

Technical Details for CVE-2024-43116

Vulnerability Analysis

The vulnerability stems from missing or insufficient CSRF protections in the Simple Local Avatars plugin. WordPress plugins are expected to validate state-changing requests using nonces generated by wp_create_nonce() and verified through check_admin_referer() or wp_verify_nonce(). When these checks are absent or improperly implemented, the plugin accepts requests based solely on the user's session cookies. An attacker who lures an authenticated user to a malicious page can submit forged requests that the WordPress backend treats as legitimate. The attack vector is network-based and requires user interaction, but no privileges of the attacker.

Root Cause

The root cause is a failure to enforce anti-CSRF tokens on sensitive plugin actions in versions up to 2.7.10. The plugin's request handlers do not adequately verify the origin or authenticity of incoming requests. This allows cross-origin form submissions to trigger privileged operations on behalf of the victim user.

Attack Vector

Exploitation occurs when an authenticated WordPress user, typically an administrator, visits an attacker-controlled page or clicks a crafted link. The malicious page submits a hidden form or issues an automated request to the vulnerable plugin endpoint. Because the victim's browser automatically attaches authentication cookies, the request executes with the victim's permissions. The vulnerability scope remains unchanged, but the impact extends to full compromise of avatar-related data and any administrative functions the plugin exposes. See the Patchstack CSRF Vulnerability Advisory for additional technical context.

Detection Methods for CVE-2024-43116

Indicators of Compromise

• Unexpected avatar changes or uploads in WordPress user profiles without corresponding user activity
• HTTP POST requests to Simple Local Avatars endpoints originating from external Referer headers
• Web server access logs showing avatar modification requests outside normal administrative workflows
• Unusual file uploads to the /wp-content/uploads/ directory tied to avatar functionality

Detection Strategies

• Monitor WordPress audit logs for avatar-related changes correlated with suspicious referer values
• Inspect HTTP request headers for cross-origin submissions targeting admin-ajax.php or plugin endpoints
• Compare plugin version against 2.7.10 and earlier across managed WordPress deployments
• Deploy a Web Application Firewall (WAF) rule set capable of identifying CSRF patterns and missing nonce parameters

Monitoring Recommendations

• Enable WordPress activity logging plugins to track profile and avatar modifications with timestamps and source IPs
• Centralize WordPress and web server logs in a SIEM for correlation against known CSRF attack patterns
• Alert on administrative actions performed shortly after users follow external links or visit unfamiliar domains

How to Mitigate CVE-2024-43116

Immediate Actions Required

• Update the Simple Local Avatars plugin to a version newer than 2.7.10 as soon as the vendor releases a patched build
• Audit WordPress user accounts and recent avatar changes for signs of unauthorized modification
• Restrict administrative access to trusted networks using IP allowlists or VPN gateways
• Educate administrators to avoid clicking untrusted links while logged into WordPress sessions

Patch Information

Review vendor channels and the Patchstack CSRF Vulnerability Advisory for the latest patched version of Simple Local Avatars. Apply updates through the WordPress plugin dashboard or by replacing plugin files manually. Verify the installed version reports higher than 2.7.10 after the update.

Workarounds

• Temporarily deactivate the Simple Local Avatars plugin until a patched release is installed
• Deploy a WAF rule blocking cross-origin POST requests to avatar-related endpoints
• Enforce SameSite=Strict or SameSite=Lax session cookies on the WordPress site to reduce CSRF exposure
• Require re-authentication for sensitive profile changes through additional plugins or custom hooks

# Configuration example
# Disable the vulnerable plugin via WP-CLI until patched
wp plugin deactivate simple-local-avatars

# Verify currently installed version
wp plugin get simple-local-avatars --field=version

# Update once a patched release is available
wp plugin update simple-local-avatars