Overview
CVE-2025-63708 details a Cross-Site Scripting (XSS) vulnerability affecting the SourceCodester AI Font Matcher (nid=18425, version dated 2025-10-10). This vulnerability allows remote attackers to inject and execute arbitrary JavaScript code within the browsers of users interacting with the affected application. This can lead to severe security breaches, including session cookie theft, account hijacking, and unauthorized actions performed on behalf of legitimate users.
Technical Details
The root cause of this XSS vulnerability lies within the application’s handling of font family names passed to the webfonts API. The application fails to properly sanitize or validate these names, allowing an attacker to inject malicious JavaScript code. The vulnerability is specifically triggered via:
- Webfonts API Handling: The application uses a webfonts API to retrieve and apply font styles. This API is vulnerable because it doesn’t properly sanitize input.
- Fetch Interception: An attacker can intercept fetch requests destined for the webfonts endpoint.
- Payload Injection: The attacker crafts a malicious fetch hook that returns controlled font data. This crafted data contains malicious JavaScript embedded within the font family name.
- Execution: When the injected font data is processed by the user’s browser, the malicious JavaScript is executed, compromising the user’s session and potentially their account.
In short, an attacker can inject malicious code by manipulating the font family name, which is then executed by the victim’s browser when processing the font data.
CVSS Analysis
Currently, a CVSS score and severity level for CVE-2025-63708 have not been assigned (N/A). However, based on the potential impact of the vulnerability (session hijacking, account compromise), it’s likely to be classified as High or Critical once a score is assigned. A high score would reflect the relative ease of exploitation and the potential for significant damage.
Possible Impact
The exploitation of CVE-2025-63708 can have serious consequences:
- Session Cookie Theft: Attackers can steal user session cookies, allowing them to impersonate legitimate users and gain unauthorized access to their accounts.
- Account Hijacking: By gaining control of a user’s session, attackers can change passwords, modify account settings, and potentially lock the legitimate user out of their account.
- Unauthorized Actions: Attackers can perform actions on behalf of the compromised user, such as making unauthorized purchases, posting malicious content, or accessing sensitive data.
- Data Breach: Depending on the application’s functionality, attackers may be able to access and exfiltrate sensitive data belonging to other users or the organization.
Mitigation and Patch Steps
To mitigate the risk posed by CVE-2025-63708, the following steps should be taken:
- Update/Patch: The primary solution is to apply the security patch released by SourceCodester (if available) for the AI Font Matcher. Check the SourceCodester website for updates.
- Input Sanitization: Implement robust input sanitization and validation for all user-supplied data, especially font family names. Ensure that any potentially malicious characters or code are properly escaped or removed before being processed by the application.
- Contextual Output Encoding: Employ contextual output encoding when displaying user-supplied data in the browser. This will prevent the browser from interpreting malicious code.
- Content Security Policy (CSP): Implement a strong Content Security Policy (CSP) to restrict the sources from which the browser can load resources. This can help prevent the execution of injected JavaScript code.
- Regular Security Audits: Conduct regular security audits and penetration testing to identify and address potential vulnerabilities in the application.
