Better Find and Replace <= 1.6.1 - Unauthenticated PHP Object Injection
Strategic Overview
- Status
- Patched in 1.6.2
- Affected Plugin
- Better Find and Replace – AI-Powered Suggestions
- Affected Version
<= 1.6.1- CVSS
- 8.3High
- Weakness type
- CWE-502 · Deserialization of Untrusted Data
- CVE
CVE-2024-39636
At a glance
CVE-2024-39636 is a high-severity Deserialization of Untrusted Data vulnerability in the Better Find and Replace WordPress plugin, affecting versions <= 1.6.1. It carries a CVSS score of 8.3 (reachable over the network; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 1.6.2; sites on affected versions should update now. Disclosed July 2024, reported by Trinh Vu (Sonicrrrr).
Vulnerability Overview
The Better Find and Replace plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.6.1 via deserialization of untrusted input from the 'str' parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no privileges on the target site. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-502: Deserialization of Untrusted Data
Better Find and Replace <= 1.6.1 carries this weakness at str, and reaching it takes no account at all. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.
A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For Better Find and Replace the fix is 1.6.2: builds <= 1.6.1 are affected, anything from 1.6.2 onward is not.
Remediation
Update to version 1.6.2, or a newer patched version
How does WordSec protect against this?
Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Better Find and Replace 1.6.2 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Login Security
External References
Related records
Other vulnerabilities in Better Find and Replace – AI-Powered Suggestions
- 8.8CVE-2025-9334: Better Find and Replace <= 1.7.7 Limited Code Injection
CVE-2025-9334 - 8.8CVE-2025-24734: Better Find and Replace Authenticated (Subscriber+)
CVE-2025-24734 - 7.2CVE-2022-1472: Better Find and Replace <= 1.3.5 Admin+ SQL Injection
CVE-2022-1472 - 6.1CVE-2021-24676: Better Find and Replace <= 1.2.8 Reflected XSS
CVE-2021-24676 - 5.4CVE-2026-3369: Better Find and Replace Stored XSS
CVE-2026-3369 - 4.4CVE-2025-53466: Better Find and Replace <= 1.7.6 Stored XSS
CVE-2025-53466 - 4.3CVE-2025-12360: Better Find and Replace <= 1.7.7 Missing Authorization
CVE-2025-12360
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