CVE-2011-2180 in Really Simple Chat
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in dereferer.php in A Really Simple Chat (ARSC) 3.3-rc2 allows remote attackers to inject arbitrary web script or HTML via the arsc_link parameter.
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Analysis
by VulDB Data Team • 01/17/2018
The vulnerability identified as CVE-2011-2180 represents a classic cross-site scripting flaw within the A Really Simple Chat 3.3-rc2 web application. This issue specifically affects the dereferer.php script which processes user input through the arsc_link parameter, creating an attack vector that enables remote threat actors to execute malicious web scripts or HTML code within the context of other users' browsers. The vulnerability stems from inadequate input validation and output sanitization mechanisms within the application's core functionality, allowing attackers to bypass security controls that should normally prevent malicious code execution.
The technical implementation of this XSS vulnerability occurs when the application fails to properly sanitize or escape user-supplied data before rendering it in web pages. In this case, the arsc_link parameter serves as the primary injection point where malicious payloads can be submitted through URL parameters or form fields. When legitimate users visit pages that display the tainted input without proper encoding or filtering, their browsers execute the injected malicious scripts, potentially leading to session hijacking, data theft, or further exploitation of the victim's browser environment. This type of vulnerability falls under CWE-79 which specifically addresses improper neutralization of input during web page generation, making it a fundamental web application security weakness.
The operational impact of this vulnerability extends beyond simple script injection, as it can be leveraged for sophisticated attack chains within the context of web application security. Attackers can craft malicious links that, when clicked by unsuspecting users, execute scripts to steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users. The vulnerability's remote nature means that attackers do not require physical access to the system or network, enabling widespread exploitation through social engineering techniques such as phishing campaigns or compromised web resources. This weakness directly relates to ATT&CK technique T1531 which involves using compromised accounts to gain access to resources, and T1059 which encompasses executing malicious code through various attack vectors including web-based applications.
Mitigation strategies for CVE-2011-2180 should focus on implementing proper input validation and output encoding mechanisms throughout the application's data flow. The primary defense involves sanitizing all user input through whitelisting approaches or comprehensive HTML escaping before rendering any content in web pages. Developers should implement Content Security Policy headers to limit script execution and prevent unauthorized code injection. Additionally, upgrading to patched versions of A Really Simple Chat or implementing web application firewalls that can detect and block XSS attack patterns would provide effective protection. Security teams should also conduct regular vulnerability assessments and penetration testing to identify similar weaknesses in other web applications, as this type of vulnerability commonly appears in legacy systems that have not received proper security updates. The remediation process should include comprehensive code review to ensure all input parameters are properly validated and that output encoding is consistently applied across all user-facing components of the application.