CVE-2011-5042 in SASHA
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in inc/lib/lib.base.php in SASHA 0.2.0 allows remote attackers to inject arbitrary web script or HTML via the instructors parameter. NOTE: the original disclosure also mentions the section_title parameter, but this was disputed by the vendor and retracted by the original researcher.
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Analysis
by VulDB Data Team • 02/13/2019
The CVE-2011-5042 vulnerability represents a classic cross-site scripting flaw in the SASHA 0.2.0 web application framework that exposes users to potential malicious code execution. This vulnerability specifically resides in the inc/lib/lib.base.php file and affects the instructors parameter handling within the application's backend processing logic. The issue stems from insufficient input validation and output sanitization mechanisms that fail to properly escape or filter user-supplied data before it is rendered in web pages. This allows remote attackers to inject arbitrary web scripts or HTML content that executes in the context of other users' browsers when they view affected pages.
The technical exploitation of this vulnerability follows standard XSS attack patterns where malicious input is crafted to bypass the application's security controls. When an attacker submits specially crafted data through the instructors parameter, the application processes this input without adequate sanitization, storing or directly outputting the malicious content to web pages. The vulnerability is classified as a reflected XSS issue since the malicious script is executed in the victim's browser when they access a page containing the injected content. This flaw operates at the application layer and leverages the trust relationship between the web application and its users, making it particularly dangerous for web applications that handle sensitive user data or administrative functions.
From an operational impact perspective, this vulnerability creates significant security risks for organizations using SASHA 0.2.0 as it can lead to session hijacking, credential theft, data exfiltration, and potential lateral movement within compromised networks. Attackers could exploit this vulnerability to steal user sessions, redirect victims to malicious sites, or inject backdoors into the application environment. The vulnerability's impact is amplified by the fact that it affects core library functionality, potentially compromising multiple application features that rely on the lib.base.php file. According to CWE standards, this vulnerability maps to CWE-79 which specifically addresses cross-site scripting flaws, while the ATT&CK framework would classify this under T1566 for credential access through malicious content and potentially T1071 for application layer protocol usage.
Organizations should implement multiple layers of mitigation to address this vulnerability effectively. The primary remediation involves input validation and output encoding of all user-supplied parameters, particularly those used in dynamic content generation. The application should employ proper HTML escaping mechanisms for all data rendered in web pages and implement Content Security Policy headers to limit script execution. Additionally, developers should conduct thorough code reviews focusing on input handling and output sanitization practices, ensuring that all parameters including instructors are properly validated against expected data formats. The vulnerability serves as a reminder of the critical importance of secure coding practices and input sanitization in preventing common web application attacks. Organizations should also consider implementing web application firewalls and regular security assessments to identify similar vulnerabilities in their application ecosystems.