CVE-2012-6142 in HTML::EP
Summary
by MITRE
Session::Cookie in the HTML::EP module 0.2011 for Perl does not properly use the Storable::thaw function, which allows remote attackers to execute arbitrary code via a crafted request, which is not properly handled when it is deserialized.
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Analysis
by VulDB Data Team • 03/09/2018
The vulnerability identified as CVE-2012-6142 resides within the HTML::EP module version 0.2011 for Perl, specifically within the Session::Cookie component that handles session management through cookie-based mechanisms. This flaw represents a critical security issue that stems from improper handling of data deserialization processes, creating a pathway for remote code execution attacks. The vulnerability is particularly concerning because it affects the fundamental session management capabilities of web applications built using this Perl module, potentially allowing attackers to gain unauthorized access to system resources and execute malicious code remotely.
The technical root cause of this vulnerability lies in the inadequate implementation of the Storable::thaw function within the Session::Cookie class. When the module processes incoming cookie data, it fails to properly validate or sanitize the serialized data before attempting to deserialize it using Storable::thaw. This improper handling creates a deserialization vulnerability that can be exploited by attackers who craft malicious cookie payloads containing serialized Perl objects. The Storable module in Perl is designed for serializing and deserializing Perl data structures, but when used without proper input validation, it becomes a vector for arbitrary code execution. The flaw specifically manifests when the deserialization process attempts to reconstruct Perl objects from attacker-controlled data, potentially executing malicious code during the reconstruction phase.
The operational impact of CVE-2012-6142 extends beyond simple privilege escalation, as it enables full remote code execution capabilities for attackers who can manipulate session cookies. This vulnerability affects web applications that rely on HTML::EP for session management, potentially compromising entire web servers or application environments. Attackers can leverage this flaw to execute arbitrary commands on the target system with the privileges of the web server process, which could lead to complete system compromise, data exfiltration, or further lateral movement within network environments. The vulnerability is particularly dangerous in multi-tenant hosting environments or applications where session management is critical for user authentication and authorization, as it could allow attackers to impersonate legitimate users or gain administrative access.
Mitigation strategies for this vulnerability require immediate attention from system administrators and security teams. The most effective approach involves upgrading to a patched version of the HTML::EP module that properly implements input validation and secure deserialization practices. Organizations should also implement network-level controls such as web application firewalls that can detect and block suspicious cookie payloads, though this represents a secondary defense mechanism. Additional protective measures include implementing proper input validation at multiple layers of the application architecture, using secure coding practices that avoid unsafe deserialization patterns, and conducting regular security assessments of Perl applications. This vulnerability aligns with CWE-502, which specifically addresses deserialization of untrusted data as a security weakness, and can be mapped to ATT&CK technique T1203, which covers exploitation of remote services through deserialization vulnerabilities. The remediation process should include thorough code reviews to ensure that all deserialization operations properly validate input data and that appropriate error handling mechanisms are implemented to prevent malicious code execution during data reconstruction processes.