CVE-2022-0945 in ShowDoc
Summary
by MITRE • 03/15/2022
Stored XSS viva axd and cshtml file upload in star7th/showdoc in GitHub repository star7th/showdoc prior to v2.10.4.
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Analysis
by VulDB Data Team • 03/17/2022
The vulnerability CVE-2022-0945 represents a critical stored cross-site scripting flaw discovered in the showdoc application hosted on GitHub under the repository star7th/showdoc. This vulnerability specifically affects versions prior to v2.10.4 and stems from insufficient input validation during file upload processes involving axd and cshtml file types. The flaw allows attackers to inject malicious scripts into the application's storage system through carefully crafted file uploads, which then execute when other users access the affected content. This vulnerability directly impacts the integrity and security of the web application by creating a persistent vector for malicious code execution within the application's environment.
The technical implementation of this vulnerability exploits the application's failure to properly sanitize user-supplied input during file upload operations. When users upload axd and cshtml files, the system does not adequately validate or escape the content before storing it in the database or file system. This lack of proper input sanitization creates an opportunity for attackers to embed malicious javascript code within these file types, which then gets executed whenever legitimate users view or interact with the uploaded content. The vulnerability operates at the intersection of file upload validation and output encoding, where the application fails to implement proper security controls to prevent script injection attacks. This flaw aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the improper handling of user input that leads to cross-site scripting vulnerabilities.
The operational impact of this stored XSS vulnerability extends beyond simple script execution, as it provides attackers with persistent access to user sessions and sensitive data within the application environment. An attacker who successfully exploits this vulnerability can steal cookies, session tokens, and potentially escalate privileges within the application. The stored nature of the vulnerability means that the malicious code persists even after the initial upload, allowing attackers to maintain access over extended periods without requiring repeated exploitation attempts. This vulnerability particularly affects web applications that rely on user-generated content and file uploads, as it transforms legitimate file upload functionality into a weapon for persistent attack vectors. The impact is amplified when considering that the vulnerability affects the showdoc application, which likely serves as a documentation platform where users may have elevated privileges or access to sensitive information.
Mitigation strategies for CVE-2022-0945 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application's file upload and content rendering processes. Organizations should immediately upgrade to showdoc version 2.10.4 or later, which contains the necessary patches to address the vulnerability. Additionally, implementing strict file type validation, content sanitization, and proper output encoding for all user-supplied content can prevent similar vulnerabilities from occurring in the future. Security measures should include validating file extensions, implementing content type checks, and ensuring that all uploaded files undergo thorough sanitization before being stored or rendered. The application should also implement proper access controls and monitoring to detect unauthorized file upload activities. These measures align with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as they address the attack vector where malicious files are uploaded to web applications to compromise user sessions and execute unauthorized code. Organizations should also consider implementing web application firewalls and content security policies to provide additional layers of protection against similar stored XSS vulnerabilities in their web applications.