Summary: A vulnerability exists in Curl, where a password used for the first host could be leaked to the followed-to host when asked to use a .netrc file for credentials and to follow HTTP redirects under certain circumstances.

Background

Curl is a widely used command-line tool and library for transferring data with URL syntax, supporting a myriad of protocols such as HTTP, HTTPS, and FTP. It serves as an indispensable tool for developers, penetration testers, and system administrators.

In this case, the vulnerability tracked as CVE-2024-11053 arises when Curl is instructed to both use a .netrc file for credentials storage and follow HTTP redirects.

The Vulnerability

When users utilize a .netrc file to store credentials for different hosts, Curl could leak the password used for the first host to the followed-to host when specific conditions are met.

Here's a simple code snippet demonstrating the issue

# .netrc file
machine example.com login john_doe password super_secret_pass
machine attacker.com

# Curl command
curl --netrc --location https://example.com/sensitive_data

If example.com redirects the request to attacker.com, the password super_secret_pass might be leaked to attacker.com due to this vulnerability.

The Exploit

An adversary could exploit this vulnerability by setting up a website with a URL that automatically redirects users to a malicious domain. If a user attempts to access this URL using Curl with both .netrc file and --location flag, the password associated with the original host may leak to the malicious domain, thus compromising the user's data stored on the original host.

To prevent this vulnerability from impacting your systems

1. Update Curl to the latest version, as the Curl development team has released a security patch addressing this issue. Versions 7.81. and later are not affected by this vulnerability.
2. Verify the authenticity and safety of the hosts you are connecting to before using Curl with a .netrc file and --location flag.
3. Use an alternate method for providing authentication credentials to Curl, such as environment variables or passing them directly via the command line (with caution, as it could expose credentials in the command history).

Final Thoughts

Curl is an essential tool for handling various network protocols; therefore, security issues such as CVE-2024-11053 significantly impact a wide range of users. By staying informed about the latest vulnerabilities and taking the necessary steps to protect your systems, you can reduce the risk of security breaches and maintain your data's privacy.

Timeline

Published on: 12/11/2024 08:15:05 UTC
Last modified on: 12/15/2024 17:15:05 UTC