Overview
The Friends plugin for WordPress, a popular content management system, has been identified as being vulnerable to a specific type of attack known as PHP Object Injection. This exploit, designated as CVE-2025-7504, can allow an authenticated attacker with subscriber-level access to potentially compromise the system or leak sensitive data. The vulnerability is of particular concern to websites that have other plugins or themes installed that contain a POP (Property Oriented Programming) chain.
Vulnerability Summary
CVE ID: CVE-2025-7504
Severity: High (7.5)
Attack Vector: Network
Privileges Required: Low (Subscriber-level access)
User Interaction: Required
Impact: Potential system compromise or data leakage
Affected Products
Product | Affected Versions
WordPress Friends Plugin | 3.5.1
How the Exploit Works
The exploit takes advantage of a vulnerability in version 3.5.1 of the Friends plugin for WordPress where the query_vars parameter is susceptible to PHP Object Injection via deserialization of untrusted input. This allows an attacker, with subscriber-level access and knowledge of the site’s SALT_NONCE and SALT_KEY, to inject a PHP Object. Notably, the vulnerability can be escalated if a POP chain is present via an additional plugin or theme, which could potentially allow the attacker to delete files, retrieve sensitive data, or execute code.
Conceptual Example Code
Here’s a conceptual HTTP POST request that an attacker might use:
POST /wp-admin/admin-ajax.php?action=friends_query_vars HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "query_vars": "serialized PHP object" }
Please note that the “serialized PHP object” placeholder should be replaced with a malicious serialized PHP object that the attacker intends to inject.
Mitigation and Recommendations
Users are advised to immediately apply the vendor-released patch to fix this vulnerability. In the absence of a patch, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as temporary mitigation. Furthermore, site owners should audit their installed plugins and themes for the presence of a POP chain, which can escalate the impact of this vulnerability.
