CVE-2022-4841 in memos
Summary
by MITRE • 12/29/2022
Cross-site Scripting (XSS) - Stored in GitHub repository usememos/memos prior to 0.9.1.
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Analysis
by VulDB Data Team • 01/26/2023
The vulnerability identified as CVE-2022-4841 represents a stored cross-site scripting flaw within the usememos/memos repository software, affecting versions prior to 0.9.1. This repository hosts a note-taking application that allows users to create and manage memos, with the vulnerability enabling malicious actors to inject persistent malicious scripts into the application's data storage. The flaw specifically manifests when user-supplied content containing malicious script code is stored within the application's database and subsequently rendered to other users without proper sanitization or encoding mechanisms. The vulnerability exists due to insufficient input validation and output encoding practices within the memo creation and display components of the application.
The technical exploitation of this stored XSS vulnerability occurs when an attacker crafts malicious content containing script payloads that are then stored in the application's backend database. When other users view these memo entries, the malicious scripts execute within their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious sites. This type of vulnerability falls under CWE-79 which specifically addresses Cross-site Scripting flaws, and aligns with ATT&CK technique T1531 which covers "Modify Application Runtime". The vulnerability's persistence stems from the application's failure to properly sanitize user input before storing it, creating a condition where malicious code remains embedded in the system and executes every time the compromised content is accessed.
The operational impact of CVE-2022-4841 extends beyond simple script execution as it can enable attackers to establish persistent access to user sessions and potentially escalate privileges within the application. An attacker could exploit this vulnerability to steal session cookies, capture user credentials, or manipulate the application's functionality to perform unauthorized actions. The stored nature of the vulnerability means that the malicious payload remains active even after the initial injection, creating a long-term threat vector that persists until the application is updated to version 0.9.1 or later. This vulnerability particularly affects collaborative environments where multiple users interact with shared memo content, as the malicious scripts can compromise all users who access the affected data.
Mitigation strategies for CVE-2022-4841 require immediate implementation of proper input sanitization and output encoding mechanisms throughout the application's data handling pipeline. Organizations should upgrade to version 0.9.1 or later of the memos application to receive the patched implementation that properly sanitizes user input and encodes output before rendering. Additional protective measures include implementing Content Security Policy headers to limit script execution, employing web application firewalls to detect and block malicious payloads, and conducting regular security audits of user input handling processes. The remediation approach should follow security best practices outlined in OWASP's XSS prevention guidelines and align with NIST SP 800-53 security controls for input validation and output encoding. Regular security training for developers on secure coding practices and input validation techniques can help prevent similar vulnerabilities in future implementations.