CVE-2022-25978 in memos
Summary
by MITRE • 02/15/2023
All versions of the package github.com/usememos/memos/server are vulnerable to Cross-site Scripting (XSS) due to insufficient checks on external resources, which allows malicious actors to introduce links starting with a javascript: scheme.
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Analysis
by VulDB Data Team • 03/18/2025
The vulnerability identified as CVE-2022-25978 affects the github.com/usememos/memos/server package, representing a critical cross-site scripting flaw that undermines web application security. This vulnerability stems from inadequate validation mechanisms within the application's handling of external resources, specifically failing to properly sanitize user input that includes hyperlinks. The flaw allows attackers to inject malicious javascript: scheme links that can execute arbitrary code within the context of a victim's browser session. Such vulnerabilities fall under the CWE-79 category of Cross-site Scripting, which is classified as a fundamental weakness in web application security that enables attackers to inject client-side scripts into web pages viewed by other users.
The technical implementation of this vulnerability occurs when the application processes user-provided content containing external links without proper sanitization of the scheme portion of URLs. When a javascript: scheme link is introduced, the application fails to validate or reject such inputs, allowing the malicious script to execute in the victim's browser. This type of vulnerability is particularly dangerous because it can be exploited through various attack vectors including user comments, shared documents, or any input field where external links are accepted. The attack chain typically involves an attacker crafting a malicious link with javascript: scheme that when clicked by a victim, executes arbitrary code within the victim's browser context. This weakness directly aligns with ATT&CK technique T1566.001 which covers spearphishing with attachments, as the malicious link could be embedded in phishing emails or documents.
The operational impact of CVE-2022-25978 extends beyond simple script execution, as it can enable a wide range of malicious activities including session hijacking, data exfiltration, credential theft, and redirection to malicious websites. An attacker could potentially steal user sessions, access sensitive information, or manipulate the application's functionality to serve as a platform for further attacks. The vulnerability affects all versions of the memos/server package, indicating a persistent flaw that has not been addressed through updates, leaving users exposed to ongoing threats. Organizations relying on this package for collaborative document management and knowledge sharing are particularly at risk, as the vulnerability can be exploited through any user interaction with external links within the application.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization mechanisms that explicitly reject or encode javascript: scheme links before processing user content. The recommended approach includes implementing a whitelist-based validation system that only allows safe URL schemes such as http:, https:, ftp:, and mailto: while rejecting any javascript: or data: schemes. Additionally, proper output encoding should be implemented when displaying user-provided content to prevent script execution even if malicious input slips through validation. Organizations should also consider implementing Content Security Policy (CSP) headers to add an additional layer of protection against XSS attacks. Regular security audits and dependency updates should be enforced to prevent similar vulnerabilities from persisting in the application ecosystem. The fix should align with security best practices outlined in OWASP Top Ten and should be implemented as part of a comprehensive web application security strategy that includes both defensive coding practices and runtime protection mechanisms.