EUVD-2025-6924

Comprehensive Technical Analysis of EUVD-2025-6924

1. Vulnerability Assessment and Severity Evaluation

The EUVD entry EUVD-2025-6924 describes a Cross-Site Scripting (XSS) vulnerability in the open-webui/open-webui software, specifically affecting versions up to and including 0.3.8. The vulnerability is located in the function responsible for constructing HTML for tooltips. This XSS vulnerability allows attackers to execute malicious scripts in the context of the victim's browser session.

Severity Evaluation:

• Base Score: 9.0
• Base Score Version: CVSS 3.0
• Base Score Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

The CVSS score of 9.0 indicates a critical vulnerability. The vector string breaks down as follows:

• AV:N (Attack Vector: Network) - The vulnerability is exploitable over the network.
• AC:L (Attack Complexity: Low) - The attack requires low complexity to exploit.
• PR:L (Privileges Required: Low) - The attacker requires low privileges to exploit the vulnerability.
• UI:R (User Interaction: Required) - The attack requires some form of user interaction.
• S:C (Scope: Changed) - The vulnerability affects a different security scope.
• C:H (Confidentiality: High) - The vulnerability has a high impact on confidentiality.
• I:H (Integrity: High) - The vulnerability has a high impact on integrity.
• A:H (Availability: High) - The vulnerability has a high impact on availability.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Phishing Emails: Attackers can send crafted links to victims, enticing them to click on malicious URLs.
• Malicious Websites: Attackers can host malicious websites that exploit the vulnerability when visited by users.
• Compromised Third-Party Content: Attackers can inject malicious scripts into third-party content that is loaded by the vulnerable application.

Exploitation Methods:

• Stored XSS: Attackers can inject malicious scripts into the application's database, which are then executed when the victim views the affected content.
• Reflected XSS: Attackers can craft URLs that contain malicious scripts, which are executed when the victim clicks on the link.

3. Affected Systems and Software Versions

Affected Software:

• open-webui/open-webui versions up to and including 0.3.8.

Affected Systems:

• Any system running the affected versions of open-webui/open-webui.
• Systems where users have administrative privileges are at higher risk due to the potential for privilege escalation.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Patching: Upgrade to a version of open-webui/open-webui that is not affected by this vulnerability.
• Input Validation: Implement strict input validation and sanitization to prevent the injection of malicious scripts.
• Content Security Policy (CSP): Implement a robust CSP to mitigate the impact of XSS attacks.

Long-Term Mitigation:

• Security Training: Educate users about the risks of phishing and the importance of not clicking on suspicious links.
• Regular Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate similar issues.
• Incident Response Plan: Develop and maintain an incident response plan to quickly address any security breaches.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations and individuals using the affected software within the European Union. The potential for data theft, unauthorized actions, and privilege escalation can lead to severe consequences, including financial loss, reputational damage, and legal repercussions under GDPR.

Regulatory Compliance:

• Organizations must ensure compliance with GDPR by implementing appropriate security measures to protect personal data.
• Failure to address this vulnerability could result in regulatory penalties and legal actions.

6. Technical Details for Security Professionals

Vulnerability Details:

• The vulnerability is located in the function that constructs HTML for tooltips within open-webui/open-webui.
• The flaw allows attackers to inject malicious scripts that are executed in the context of the victim's browser session.

Exploitation Steps:

1. Identify the Vulnerable Function: Locate the function responsible for constructing HTML for tooltips.
2. Inject Malicious Script: Craft a payload that injects a malicious script into the tooltip HTML.
3. Deliver the Payload: Use phishing emails, malicious websites, or compromised third-party content to deliver the payload to the victim.
4. Execute the Script: The malicious script is executed when the victim interacts with the tooltip, allowing the attacker to perform unauthorized actions.

Detection and Monitoring:

• Implement logging and monitoring to detect unusual activities that may indicate an XSS attack.
• Use web application firewalls (WAFs) to detect and block malicious input.

Conclusion: The XSS vulnerability in open-webui/open-webui versions up to and including 0.3.8 is critical and requires immediate attention. Organizations should prioritize patching affected systems, implementing robust security measures, and educating users to mitigate the risk of exploitation. Compliance with GDPR and other regulatory requirements is essential to avoid legal and financial repercussions.