CVE-2005-4670 in Php Lnkx
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in message.php in CityPost Automated Link Exchange (LNKX) allows remote attackers to inject arbitrary web script or HTML via the msg parameter.
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Analysis
by VulDB Data Team • 05/20/2025
The vulnerability identified as CVE-2005-4670 represents a classic cross-site scripting flaw within the CityPost Automated Link Exchange (LNKX) system, specifically affecting the message.php component. This issue resides in the web application's handling of user input parameters, creating a pathway for malicious actors to execute unauthorized code within the context of other users' browsers. The vulnerability is categorized under CWE-79 which specifically addresses improper neutralization of input during web page generation, making it a fundamental web application security weakness that has persisted across numerous systems throughout the years. The affected parameter, msg, serves as the entry point for attackers to inject malicious scripts that can be executed when other users view the affected page.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the message.php script. When the application processes the msg parameter without proper sanitization, it directly incorporates user-supplied data into the web page response without appropriate HTML escaping or context-aware encoding. This allows attackers to inject malicious JavaScript code, HTML tags, or other harmful content that gets executed in the victim's browser when they encounter the compromised page. The vulnerability is classified as a reflected XSS attack since the malicious payload is embedded in the URL parameters and reflected back to the user without proper sanitization. This type of attack pattern aligns with ATT&CK technique T1566.001 which focuses on spearphishing attachments and T1566.002 which covers spearphishing via web links, demonstrating how such vulnerabilities can be leveraged in social engineering campaigns.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it can enable attackers to perform a wide range of malicious activities within the compromised user sessions. Attackers can leverage this vulnerability to steal session cookies, redirect users to malicious sites, modify page content, or even escalate privileges within the application if the user has elevated access rights. The severity of this issue is particularly concerning given that it affects an automated link exchange system, which typically serves as a critical infrastructure component for web traffic management and content distribution. The vulnerability creates a persistent threat vector that can be exploited across multiple users and sessions, potentially leading to widespread compromise of the application ecosystem. This type of vulnerability also increases the attack surface for more sophisticated attacks, as it can serve as a stepping stone for privilege escalation or lateral movement within the network.
Mitigation strategies for CVE-2005-4670 should focus on implementing robust input validation and output encoding mechanisms throughout the application. The primary defense involves sanitizing all user input parameters, particularly those used in dynamic page generation, by employing proper HTML escaping techniques before rendering content. Organizations should implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts and establish proper input validation routines that reject or sanitize potentially malicious content. Additionally, the application should employ context-aware encoding based on the output context, such as HTML, JavaScript, or URL encoding, to prevent injection attacks. Regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other components of the application. The implementation of web application firewalls and security monitoring systems can also provide additional layers of protection against exploitation attempts. Organizations should also consider implementing proper error handling and logging mechanisms to detect and respond to potential exploitation attempts, while ensuring that all application components are regularly updated and patched according to established security protocols.