2025-02-13
Just finished my writeup about CVE-2025-23369, an interesting SAML authentication bypass on GitHub Enterprise Server I reported last year. You can read about it here: CVE-2025-23369 Writeup.
Practice-Verified Code and Commands
To understand and replicate the vulnerability, you can use the following commands and code snippets:
- Setting up a local SAML Identity Provider (IdP) for testing:
docker run -d --name=saml-idp -p 8080:8080 -p 8443:8443 -e SIMPLESAMLPHP_SP_ENTITY_ID=github-enterprise -e SIMPLESAMLPHP_SP_ASSERTION_CONSUMER_SERVICE=http://localhost:8080/acs kristophjunge/test-saml-idp
Configuring GitHub Enterprise Server to use the local IdP:
ghe-saml-auth-configure --idp-url https://localhost:8443/simplesaml/saml2/idp/metadata.php --certificate /path/to/idp/certificate.crt --entity-id github-enterprise
3. Exploiting the SAML Authentication Bypass:
import requests
url = "https://github-enterprise.example.com/saml/consume"
payload = {
"SAMLResponse": "malicious_saml_response_here",
"RelayState": ""
}
headers = {
"Content-Type": "application/x-www-form-urlencoded"
}
response = requests.post(url, data=payload, headers=headers)
print(response.text)
4. Mitigation Steps:
ghe-saml-auth-disable ghe-saml-auth-configure --idp-url https://secure-idp.example.com/saml2/idp/metadata.php --certificate /path/to/secure/certificate.crt --entity-id github-enterprise
What Undercode Say
The CVE-2025-23369 vulnerability highlights the importance of secure SAML authentication configurations in enterprise environments. SAML (Security Assertion Markup Language) is widely used for single sign-on (SSO) implementations, but misconfigurations can lead to severe security breaches. In this case, the bypass allowed attackers to impersonate legitimate users, potentially gaining unauthorized access to sensitive repositories and data.
To mitigate such vulnerabilities, always ensure that your SAML IdP is securely configured and regularly updated. Use strong cryptographic keys and certificates, and validate SAML responses thoroughly. Additionally, implement robust logging and monitoring to detect and respond to suspicious activities promptly.
For further reading on SAML security best practices, refer to the following resources:
– SAML Security Cheat Sheet
– GitHub Enterprise SAML Documentation
In conclusion, always stay vigilant and proactive in securing your authentication mechanisms. Regularly review and update your security configurations, and stay informed about the latest vulnerabilities and patches. By doing so, you can significantly reduce the risk of unauthorized access and protect your organization’s critical assets.
Remember, security is a continuous process, not a one-time setup. Keep your systems updated, conduct regular security audits, and foster a culture of security awareness within your organization. Stay safe and secure!
References:
Hackers Feeds, Undercode AI
