CVE-2025-66073 in WP Webhooks Plugin
Summary
by MITRE • 11/21/2025
Deserialization of Untrusted Data vulnerability in Cozmoslabs WP Webhooks wp-webhooks allows Object Injection.This issue affects WP Webhooks: from n/a through <= 3.3.8.
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Analysis
by VulDB Data Team • 11/22/2025
The CVE-2025-66073 vulnerability represents a critical deserialization flaw in the Cozmoslabs WP Webhooks plugin for WordPress, specifically impacting versions through 3.3.8. This vulnerability falls under the CWE-502 category, which specifically addresses deserialization of untrusted data, making it a prime target for object injection attacks. The flaw exists within the plugin's handling of webhook data processing where user-controllable input is directly deserialized without proper validation or sanitization measures. Attackers can exploit this weakness by crafting malicious serialized objects that, when processed by the vulnerable plugin, execute arbitrary code on the target WordPress installation.
The technical implementation of this vulnerability stems from the plugin's failure to properly validate input data during the deserialization process. When the wp-webhooks plugin processes incoming webhook requests, it accepts serialized data that should be treated as untrusted input. The vulnerability manifests when the plugin's deserialization logic does not perform adequate checks to ensure that the serialized object originates from a legitimate source or conforms to expected data structures. This lack of input validation creates a pathway for attackers to inject malicious objects that can be executed during the deserialization phase, potentially leading to complete system compromise.
The operational impact of this vulnerability extends far beyond simple data corruption or denial of service conditions. An attacker who successfully exploits this vulnerability can achieve arbitrary code execution on the affected WordPress server, potentially leading to full system compromise. The attack surface is particularly concerning because WordPress installations are often deployed in environments where they have elevated privileges and access to sensitive data. This vulnerability can be exploited through various attack vectors including webhook configuration manipulation, malicious payload injection, or even social engineering attacks that trick administrators into configuring malicious webhook endpoints. The severity is amplified by the fact that the plugin is designed to process external data, making it a natural target for attackers seeking to exploit deserialization weaknesses.
Mitigation strategies for CVE-2025-66073 should prioritize immediate plugin updates to versions that address the deserialization flaw. Organizations should also implement network-level controls to restrict webhook endpoint access, particularly limiting external communication to trusted sources only. The implementation of proper input validation and sanitization measures within the plugin's deserialization logic is essential, along with the adoption of secure coding practices that avoid direct deserialization of untrusted data. Security monitoring should include detection of unusual webhook processing patterns and anomalous deserialization activities. Additionally, administrators should consider implementing web application firewalls to filter potentially malicious serialized data before it reaches the plugin's processing logic. This vulnerability aligns with ATT&CK technique T1059.007 for command and script injection, emphasizing the need for comprehensive security controls that address both the immediate vulnerability and broader attack surface considerations.