CVE-2012-5495 in Plone
Summary
by MITRE
python_scripts.py in Plone before 4.2.3 and 4.3 before beta 1 allows remote attackers to execute Python code via a crafted URL, related to "go_back."
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Analysis
by VulDB Data Team • 03/13/2019
The vulnerability identified as CVE-2012-5495 represents a critical remote code execution flaw within the Plone content management system. This vulnerability specifically targets the python_scripts.py component and affects Plone versions prior to 4.2.3 and 4.3 beta 1. The issue stems from insufficient input validation and sanitization mechanisms that allow malicious actors to inject and execute arbitrary Python code through carefully crafted URLs. The vulnerability is particularly dangerous because it enables remote attackers to gain full control over the affected system without requiring authentication or prior access.
The technical flaw manifests in the improper handling of URL parameters within the "go_back" functionality of Plone's python_scripts.py module. When a user navigates to a specially crafted URL containing malicious Python code within the go_back parameter, the system fails to properly validate or sanitize this input before executing it. This represents a classic command injection vulnerability that falls under CWE-94, which defines weaknesses related to the execution of arbitrary code. The vulnerability exists because the application directly incorporates user-supplied input into Python code execution contexts without adequate security controls or input filtering mechanisms.
The operational impact of this vulnerability is severe and multifaceted. Remote attackers can leverage this flaw to execute arbitrary commands on the affected Plone server, potentially leading to complete system compromise. Attackers may use this vulnerability to install backdoors, exfiltrate sensitive data, modify content, or establish persistent access to the system. The vulnerability affects not just individual websites but entire Plone installations that have not been patched, making it particularly dangerous for organizations relying on this CMS platform. The lack of authentication requirements means that any user with access to the web application can exploit this vulnerability, amplifying the potential attack surface and impact.
Organizations affected by this vulnerability should immediately implement the recommended mitigations and patches provided by the Plone development team. The primary solution involves upgrading to Plone version 4.2.3 or later, which includes proper input validation and sanitization for the python_scripts.py module. Additionally, network-level protections such as web application firewalls and intrusion detection systems should be configured to monitor for suspicious URL patterns containing Python code execution attempts. Security administrators should also implement proper access controls and regularly audit system logs for any unauthorized access attempts. This vulnerability demonstrates the critical importance of input validation and the principle of least privilege in web application security, aligning with ATT&CK technique T1059.006 for execution through Python scripts, and emphasizes the need for comprehensive security testing and regular vulnerability assessments to prevent such critical flaws from being exploited in production environments.