CVE-2021-44566 in RosarioSIS
Summary
by MITRE • 02/24/2022
A Cross Site Scripting (XSS) vulnerability exists in RosarioSIS before 4.3 via the SanitizeMarkDown function in ProgramFunctions/MarkDownHTML.fnc.php.
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Analysis
by VulDB Data Team • 02/26/2022
The vulnerability CVE-2021-44566 represents a critical cross site scripting flaw in RosarioSIS version 4.2 and earlier, specifically within the SanitizeMarkDown function located in ProgramFunctions/MarkDownHTML.fnc.php. This issue arises from insufficient input validation and sanitization of markdown content, creating an avenue for malicious actors to inject arbitrary javascript code into the application's output. The vulnerability demonstrates a classic weakness in web application security where user-supplied content intended for markdown processing is not properly escaped or filtered before being rendered in the browser context. The affected component serves as a markdown rendering utility that processes user-generated content, making it a prime target for attackers seeking to exploit client-side vulnerabilities.
The technical implementation of this vulnerability stems from the inadequate sanitization process within the SanitizeMarkDown function, which fails to properly escape or remove potentially dangerous characters and script tags from markdown input. When users submit content containing markdown syntax that includes embedded javascript payloads, the function does not sufficiently validate or sanitize these inputs before they are processed and displayed to other users. This flaw allows attackers to craft malicious markdown content that, when rendered by the application, executes arbitrary javascript code within the context of other users' browsers. The vulnerability specifically affects the markdown processing pipeline, where the function should have implemented proper output encoding or content security measures but failed to do so adequately. This weakness can be categorized under CWE-79 as a failure to sanitize or incorrectly sanitize user supplied input, making it a direct implementation of the common web application vulnerability pattern.
The operational impact of this vulnerability is severe as it enables attackers to perform session hijacking, defacement of application content, data theft, and potentially full compromise of user accounts. When exploited, the XSS vulnerability allows unauthorized individuals to execute malicious scripts in the context of other users' browsers, potentially stealing session cookies, modifying application behavior, or redirecting users to malicious sites. The attack surface extends to any user who views content processed through the vulnerable markdown function, making it particularly dangerous in collaborative environments where multiple users interact with shared content. The vulnerability can be exploited through various attack vectors including direct injection in form fields, file uploads, or even through API endpoints that accept markdown content. This creates a persistent threat that can affect both authenticated and unauthenticated users depending on the application's configuration and access controls.
Mitigation strategies for CVE-2021-44566 should focus on implementing proper input validation and output encoding mechanisms within the SanitizeMarkDown function. The most effective approach involves updating to RosarioSIS version 4.3 or later, which contains the necessary patches to address the vulnerability. Organizations should also implement comprehensive content sanitization that removes or encodes dangerous elements from user-supplied markdown input, including javascript protocols, event handlers, and potentially malicious html tags. The implementation should follow established security practices such as using libraries specifically designed for safe markdown processing and ensuring that all user-generated content is properly escaped before rendering. Additionally, organizations should consider implementing content security policies to prevent execution of unauthorized scripts, and conduct regular security testing including automated scanning and manual penetration testing to identify similar vulnerabilities in other components of the application. This vulnerability aligns with ATT&CK technique T1059.007 for scripting and T1566.001 for spearphishing attachments, indicating the need for both application-level and user awareness mitigations.