Stop Spammers Security <= 2022.5 - Unauthenticated PHP Object Injection

9.8
Deserialization of Untrusted Data
CVE CVE-2022-4120
CVSS 9.8 (Critical)
Publicly Published December 5, 2022
Last Updated December 9, 2022
Researcher Seryeon Ham

Description

The Stop Spammers Security plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2022.5 via deserialization of untrusted input when issuing a CPATCHA challenge. This allows unauthenticated attackers to inject a PHP Object. No POP chain is present in the vulnerable plugin. 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. Note: The official PHP recommendation is not to pass untrusted input to unserialize even if the allowed_classes option is set to false.

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Vulnerability Details for Stop Spammers Classic

Software Type Plugin
Software Slug stop-spammer-registrations-plugin (view on wordpress.org)
Patched? Yes
Remediation Update to version 2022.6, or a newer patched version
Affected Version
  • <= 2022.5
Patched Version
  • 2022.6

Recent vulnerabilities in Stop Spammers Classic

# Title CVE ID CVSS Researchers Date
1 Stop Spammers Classic <= 2026.3 - Unauthenticated Stored Cross-Site Scripting CVE-2026-48876 7.2 Peleg Nagli (ultrared.ai) June 1, 2026
2 Stop Spammers Classic <= 2026.1 - Cross-Site Request Forgery via Email Allowlist CVE-2025-14795 4.3 JoanClarke2 January 27, 2026
3 Anti-Spam: Spam Protection | Block Spam Users, Comments, Forms <= 2024.7 - Cross-Site Request Forgery to Multiple Administrative Actions CVE-2025-2935 5.4 Noah Stead (TurtleBurg) June 5, 2025
4 Stop Spammers Security | Block Spam Users, Comments, Forms <= 2024.4 - Cross-Site Request Forgery (CSRF) via sfs_process CVE-2023-7065 5.4 Lucio Sá May 3, 2024
5 Stop Spammers Security <= 2022.6 - Authenticated (Admin+) Stored Cross-Site Scripting CVE-2023-2489 4.4 Erwan LR May 15, 2023
6 Stop Spammers Security <= 2022.6 - Reflected Cross-Site Scripting CVE-2023-2488 6.1 Erwan LR May 15, 2023
7 Stop Spammers Security <= 2021.17 - Authenticated (Admin+) Stored Cross-Site Scripting CVE-2021-24517 4.8 swapnil subhash bodekar August 9, 2021
8 Stop Spammers <= 2021.8 - Reflected Cross-Site Scripting CVE-2021-24245 6.1 Hosein_vita April 8, 2021

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