CVE-2026-66567 in Anesta Plugin
Summary
by MITRE • 10/10/2026
Unauthenticated PHP Object Injection in Anesta <= 1.5.3 versions.
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Analysis
by VulDB Data Team • 10/10/2026
The vulnerability identified as an unauthenticated PHP object injection flaw within Anesta versions prior to or equal to 1.5.3 represents a critical security deficiency that allows attackers to execute arbitrary code on the target server without requiring valid credentials. This type of vulnerability stems from the improper handling of user-supplied input during the deserialization process, where data is converted back into PHP objects. In many content management systems and web applications, serialization is used for caching sessions or storing complex state information. When an application accepts serialized data from untrusted sources without validating its integrity or ensuring that only expected classes are instantiated, it creates a vector for exploitation known as insecure deserialization.
The technical root cause lies in the application's failure to enforce strict type checking and allow-listing of serializable classes during the unserialization phase. An attacker can craft a malicious payload containing a serialized object with properties set to trigger dangerous magic methods such as __destruct, __wakeup, or __toString within specific PHP classes available on the server. By manipulating these objects, the attacker can induce side effects that lead to remote code execution, data exfiltration, or denial of service conditions. This flaw is particularly severe because it does not require authentication, meaning any anonymous user interacting with the application interface can potentially exploit this weakness to gain full control over the underlying system.
From an operational perspective, the impact of this vulnerability extends far beyond simple unauthorized access. Successful exploitation allows a threat actor to take complete administrative control of the web server hosting Anesta. This includes the ability to read sensitive configuration files containing database credentials and API keys, modify website content to deface pages or inject malicious scripts for cross-site scripting attacks against visitors, and pivot into internal network segments if the server is part of a larger infrastructure. The lack of authentication requirements significantly lowers the barrier to entry for attackers, enabling automated scanning tools to rapidly identify and exploit vulnerable instances across the internet at scale.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-502 Deserialization of Untrusted Data and CWE-94 Improper Control of Generation of Code PHP Object Injection. In terms of offensive security frameworks, it maps to MITRE ATT&CK techniques including T1078 Valid Accounts if the attacker escalates privileges after initial access, but primarily falls under code execution vectors associated with web application attacks like T1505 Server Software Component: Web Shell or general remote code execution patterns. The exploitation typically involves crafting a specific HTTP request that includes the malicious serialized payload in parameters such as cookies, POST data, or URL arguments depending on how Anesta processes input streams.
Mitigation strategies must prioritize immediate patching to version 1.6.0 or later where this issue has been resolved by developers through rigorous input validation and secure deserialization practices. Organizations should implement strict allow-lists for serializable classes using mechanisms like PHP's SPL autoloaders with custom filters that prevent the instantiation of unexpected types. Additionally, deploying a Web Application Firewall can provide temporary protection by detecting patterns associated with serialized payloads containing dangerous class names or magic methods. Regular security audits and static code analysis tools configured to flag insecure deserialization calls are essential for maintaining long-term resilience against such vulnerabilities in PHP-based applications.