CVE-2022-44031 is a persistent Cross-Site Scripting (XSS) vulnerability affecting Redmine project management software versions prior to 4.2.9 and 5.0.x versions before 5.0.4. The vulnerability arises from improper sanitization of the blockquote syntax within Textile-formatted fields, which are used to format text input in Redmine. Textile is a lightweight markup language that Redmine supports for formatting content such as issue descriptions, comments, and wiki pages. Due to insufficient input validation and sanitization, an attacker can inject malicious JavaScript code into Textile-formatted fields using the blockquote syntax. When other users view the affected content, the malicious script executes in their browsers, leading to persistent XSS. This type of XSS is particularly dangerous because the malicious payload is stored on the server and served to multiple users, increasing the attack surface. The CVSS v3.1 base score is 6.1 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), and low impact on confidentiality and integrity (C:L, I:L), with no impact on availability (A:N). The scope change means the vulnerability affects components beyond the initially vulnerable component, potentially impacting other parts of the system or users. No known exploits in the wild have been reported, and no official patch links are provided in the data, but Redmine has released fixed versions 4.2.9 and 5.0.4 to address this issue. The vulnerability is categorized under CWE-79, which covers improper neutralization of input during web page generation leading to XSS.

For European organizations using Redmine for project management, issue tracking, or collaboration, this vulnerability poses a risk of persistent XSS attacks that can compromise user sessions, steal sensitive information such as authentication tokens, or perform actions on behalf of users. Since Redmine is often used internally within organizations, exploitation could lead to unauthorized access to project data, leakage of confidential information, or disruption of workflows. The scope change in the vulnerability means that the impact could extend beyond the immediate Textile formatter, potentially affecting other integrated components or plugins. Although the confidentiality and integrity impacts are rated low, the persistent nature of the XSS can facilitate more complex attacks like phishing, session hijacking, or privilege escalation if combined with other vulnerabilities. The requirement for user interaction (viewing the malicious content) limits the attack vector but does not eliminate risk, especially in environments with many users accessing shared Redmine instances. The lack of known exploits in the wild suggests limited active targeting so far, but the presence of a public CVE and medium severity score means attackers could develop exploits. European organizations with public-facing or widely accessed Redmine installations are at higher risk. Additionally, sectors with strict data protection regulations (e.g., GDPR) must consider the compliance implications of potential data leakage or unauthorized access resulting from exploitation.

1. Upgrade Redmine installations to version 4.2.9 or 5.0.4 or later, where the vulnerability has been fixed. 2. If immediate upgrade is not feasible, implement strict input validation and sanitization on Textile-formatted fields, especially those accepting blockquote syntax, to neutralize potentially malicious scripts. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers accessing Redmine. 4. Limit user permissions to reduce the number of users who can create or edit Textile-formatted content, minimizing the risk of malicious content injection. 5. Conduct regular security audits and code reviews of any custom plugins or extensions that interact with Textile formatting to ensure they do not introduce similar vulnerabilities. 6. Educate users about the risks of clicking on suspicious links or content within Redmine, as user interaction is required for exploitation. 7. Monitor Redmine logs and user activity for unusual behavior that could indicate exploitation attempts. 8. Consider isolating Redmine instances behind VPNs or internal networks if public access is not required, reducing exposure. 9. Implement web application firewalls (WAF) with rules targeting XSS payloads, specifically those exploiting Textile syntax if possible. These measures go beyond generic advice by focusing on the specific Textile formatter and blockquote syntax, user permission management, and layered defenses tailored to Redmine deployments.