QGIS is a free, open source, cross platform geographical information system (GIS) The repository contains a GitHub Actions workflow called pre-commit checks that, before commit 76a693cd91650f9b4e83edac525e5e4f90d954e9, was vulnerable to remote code execution and repository compromise because it used the pull_request_target trigger and then checked out and executed untrusted pull request code in a privileged context. Workflows triggered by pull_request_target ran with the base repositorys credentials and access to secrets. If these workflows then checked out and executed code from the head of an external pull request (which could have been attacker controlled), the attacker could have executed arbitrary commands with elevated privileges. This insecure pattern has been documented as a security risk by GitHub and security researchers. Commit 76a693cd91650f9b4e83edac525e5e4f90d954e9 removed the vulnerable code.
Weakness
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.