CVE-2005-4455 in LiveJournal
Summary
by MITRE
cleanhtml.pl 1.129 in LiveJournal CVS before Dec 13 2005 allows remote attackers to inject scripting languages via the XSL namespace in XML, via vectors such as customview.cgi.
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Analysis
by VulDB Data Team • 08/04/2017
The vulnerability described in CVE-2005-4455 represents a significant security flaw in the LiveJournal blogging platform's XML processing functionality. This issue affects the cleanhtml.pl script version 1.129 which was part of the LiveJournal CVS repository prior to December 13, 2005. The vulnerability specifically targets the handling of XML data within the customview.cgi component, creating a potential attack vector that could be exploited by remote adversaries to execute malicious code.
The technical flaw stems from insufficient input validation and sanitization of XML namespace declarations, particularly those involving the XSL namespace. When the cleanhtml.pl script processes XML data containing malicious XSL namespace declarations, it fails to properly filter or escape these elements before rendering them in the web interface. This allows attackers to inject arbitrary scripting code that can be executed in the context of a victim's browser session. The vulnerability operates through XML external entity processing where the XSL namespace can be manipulated to include malicious content that bypasses normal security controls.
The operational impact of this vulnerability extends beyond simple cross-site scripting attacks, as it enables attackers to potentially execute arbitrary code on affected systems. This could lead to complete compromise of user accounts, data exfiltration, or the ability to perform unauthorized actions on behalf of legitimate users. The remote nature of the attack means that exploitation does not require physical access to the target system, making it particularly dangerous for web applications. Attackers could craft malicious XML payloads that, when processed by the vulnerable cleanhtml.pl script, would execute in the victim's browser context.
This vulnerability aligns with CWE-74, which describes improper neutralization of special elements used in XML external entity references. The flaw also maps to ATT&CK technique T1213.002, which covers data from external sources, as the vulnerability exploits the processing of external XML data. The attack vector demonstrates a classic case of XML injection where namespace declarations are manipulated to bypass security controls. Organizations using LiveJournal or similar platforms should implement proper input validation, sanitize all XML namespace declarations, and ensure that XSL transformations are properly restricted to prevent unauthorized code execution. Additionally, regular security updates and patches should be applied to address known vulnerabilities in third-party components.
The remediation strategy involves updating the cleanhtml.pl script to properly validate and sanitize all XML namespace declarations, particularly those involving XSL namespaces. Implementing proper XML parsing libraries that enforce strict namespace validation and disabling unnecessary external entity processing would significantly reduce the attack surface. Organizations should also consider implementing web application firewalls to detect and block suspicious XML payloads, and establish proper input validation controls that prevent malicious namespace declarations from being processed by the application. Regular security assessments of XML processing components and maintaining up-to-date security patches for all third-party software components remain critical defensive measures against similar vulnerabilities.