CVE-2004-1711 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in post.php in Moodle before 1.3 allows remote attackers to inject arbitrary web script or HTML via the reply parameter.
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Analysis
by VulDB Data Team • 05/24/2019
The vulnerability identified as CVE-2004-1711 represents a critical cross-site scripting flaw discovered in Moodle version 1.3 and earlier, specifically within the post.php script. This weakness resides in how the application processes user input through the reply parameter, creating an avenue for malicious actors to execute arbitrary web scripts or HTML code within the context of other users' browsers. The vulnerability operates under the Common Weakness Enumeration framework as CWE-79, which categorizes it as a weakness related to improper neutralization of input during web output, making it a classic example of an injection vulnerability that undermines web application security.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input containing script code within the reply parameter of the post.php endpoint. When this crafted content is processed and displayed to other users who visit the affected page, the embedded scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The flaw demonstrates a failure in proper input validation and output encoding mechanisms, where user-supplied data flows directly into web responses without adequate sanitization or escaping of special characters that could be interpreted as executable code by web browsers.
From an operational perspective, this vulnerability poses significant risks to Moodle deployments since it enables attackers to compromise the security of entire user communities within the learning management system. The impact extends beyond simple data theft to potential complete system compromise, as attackers can leverage the XSS vector to establish persistent access through session manipulation or by redirecting users to malicious sites that can harvest credentials. The vulnerability particularly affects educational institutions using Moodle for online learning, where user trust and data confidentiality are paramount, and the attack surface includes not just administrators but all users who may be tricked into viewing malicious posts.
Security mitigations for this vulnerability primarily involve implementing proper input validation and output encoding techniques that align with established security frameworks and best practices. Organizations should upgrade to Moodle version 1.3 or later, which includes fixes for this specific XSS vulnerability, while also implementing comprehensive input sanitization measures that prevent malicious code injection. The remediation strategy should incorporate the principles outlined in the OWASP Top Ten and the ATT&CK framework's web application attack patterns, emphasizing the importance of context-specific output encoding, parameter validation, and the implementation of Content Security Policy headers to limit the execution of unauthorized scripts. Additionally, regular security assessments and code reviews should be conducted to identify and address similar vulnerabilities in other components of the Moodle platform and associated web applications.