CVE-2022-0938 in ShowDoc
Summary
by MITRE • 03/14/2022
Stored XSS via file upload in GitHub repository star7th/showdoc prior to v2.10.4.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/16/2022
The vulnerability identified as CVE-2022-0938 represents a critical stored cross-site scripting flaw discovered in the showdoc repository management system developed by star7th. This vulnerability specifically affects versions prior to v2.10.4 and stems from inadequate input validation and sanitization mechanisms within the file upload functionality. The flaw allows authenticated attackers with repository write permissions to upload malicious files that contain cross-site scripting payloads, which are subsequently executed when other users view the uploaded content. The vulnerability operates through a classic stored XSS attack vector where malicious code is persistently stored on the server and executed in the context of other users' browsers, making it particularly dangerous for collaborative environments where multiple users interact with shared repositories.
The technical implementation of this vulnerability involves the failure to properly sanitize file names and content during the upload process within the showdoc application. When users upload files to the repository, the system does not adequately validate or escape special characters that could be interpreted as HTML or JavaScript code. This weakness enables attackers to embed malicious scripts within file metadata or content that gets rendered without proper sanitization. The vulnerability is classified under CWE-79 as a Cross-Site Scripting flaw, specifically manifesting as a stored XSS variant where the malicious payload is permanently stored on the server and executed during subsequent user interactions. The attack requires minimal privileges since only write access to the repository is necessary, making it accessible to users who have been granted contributor-level permissions.
The operational impact of CVE-2022-0938 extends beyond simple script execution, as it creates persistent security risks for organizations relying on the showdoc platform for documentation management. When exploited, the vulnerability allows attackers to execute arbitrary JavaScript code in victims' browsers, potentially enabling session hijacking, credential theft, or redirection to malicious sites. The stored nature of the vulnerability means that once a malicious file is uploaded, all subsequent users who access the repository content will be exposed to the attack without any additional interaction required from the attacker. This persistent threat makes the vulnerability particularly dangerous in environments where documentation repositories contain sensitive information or where multiple team members regularly access shared documentation. The impact is amplified in continuous integration environments where automated documentation generation might inadvertently execute malicious payloads, creating cascading security issues.
Organizations utilizing the showdoc platform should immediately implement comprehensive mitigation strategies to address CVE-2022-0938. The primary recommendation involves upgrading to version 2.10.4 or later, which includes proper input validation and output sanitization mechanisms. Additionally, administrators should implement strict file upload policies that restrict file types and enforce rigorous content validation procedures. The mitigation approach should incorporate proper HTML escaping and content security policy implementations to prevent script execution in user-generated content contexts. Security teams should also consider implementing network-based intrusion detection systems to monitor for suspicious file upload activities and establish regular security audits of repository content. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access through web application exploitation and session management flaws, requiring organizations to strengthen their application security posture and user access controls to prevent unauthorized privilege escalation.