The Gitea 1.22.0 version has been identified as having a stored cross-site scripting (XSS) vulnerability. This flaw allows attackers to inject malicious scripts into web pages that are then served to other users. As the scripts are stored on the server, any user who accesses the affected page unknowingly executes the malicious code. This vulnerability poses significant risks, especially for applications like Gitea, which are often used for collaborative code development.
Understanding Stored XSS
Stored XSS occurs when user input is stored in a database and later rendered on web pages without proper sanitization. Attackers can exploit this by submitting payloads that execute harmful scripts when another user accesses the compromised webpage. Below are some characteristics:
- Persistent threat: The malicious code persists on the server until it is deleted.
- Hard to detect: Users may not be aware of the injected scripts until it is too late.
- Wide reach: Any user without strong security measures can fall victim to the attack.
Entry Points for the Vulnerability
In Gitea 1.22.0, the entry points for this stored XSS vulnerability primarily include:
- User Comments: Any features allowing user comments can be exploited if they include unsanitized inputs.
- Repository Descriptions: Descriptions that allow HTML or JavaScript inputs without proper validation.
- Issue Tracking System: Input fields for issues that are displayed to all users can be a significant risk.
HTTP Methods and Authentication
This vulnerability can be triggered using the POST HTTP method, where a user sends a payload to the server for storage. The exploit does not require authenticated access, making it especially dangerous. An unauthorized attack can easily lead to widespread impact, affecting numerous users.
Technical Payload Example
Here is an example of a payload that can be submitted through a vulnerable entry point:
Payload: <script>alert(document.cookie)</script>
This simple payload attempts to steal a user’s cookies through a JavaScript alert dialog. Once stored, any user viewing the associated page will execute this script, potentially exposing sensitive data to the attacker.
Execution Flow of the Vulnerability
To better understand how this vulnerability operates, consider the following ASCII flow diagram:
User -> [Submit Payload] -> Gitea Server
|
[Store Payload]
|
[Display Page to Other Users]
|
[Execute Malicious Script]
|
[Steal Cookies/Other Data]
Mitigation Approaches
Addressing this vulnerability involves implementing strict data validation and sanitization measures. Although users should remain vigilant, developers and administrators can follow these guidelines:
- Input Validation: Ensure any input fields properly filter and sanitize user inputs. Disallow HTML tags where unnecessary.
- Output Encoding: Encode output data to mitigate script execution. This is particularly crucial for user-generated content.
- Content Security Policy: Implement Content Security Policy (CSP) headers to limit the types of content that can be loaded and executed on the web application.
Additional Attacks Related to XSS
Beyond the traditional cookie-stealing attacks, stored XSS can lead to other severe outcomes:
- Session Hijacking: Attackers can exploit stolen session tokens to impersonate users.
- Phishing Attempts: XSS can redirect users to malicious sites that capture personal data.
- Malware Distribution: Payloads can serve scripts that download malware onto the user’s machine.
By remaining aware of these potential exploits, Gitea users can better protect themselves against various security threats.
Final Thoughts
The Gitea 1.22.0 stored XSS vulnerability showcases the importance of proper input validation. Developers should prioritize security measures to protect users from malicious scripts. Utilizing effective mitigation techniques can significantly reduce the risk of exploitation.
For organizations that require comprehensive security assessments, SecureLayer7 offers offensive security services and an API security scanner designed to identify and rectify vulnerabilities before they can be exploited. Investing in a robust security strategy is imperative to safeguard sensitive information and code repositories.
Credit: Exploit Database (https://www.exploit-db.com/exploits/52077)
