How the CVE Works:
This vulnerability in Keycloak (CVE-2025-XXXX) arises due to improper authorization in the Organization Mapper feature. The flaw allows unauthorized users to claim membership in an organization based solely on email or username patterns. When self-registration is enabled without proper restrictions, attackers can craft usernames or emails that match the organization’s naming pattern. This results in the attacker’s token containing false organization claims, misleading applications that rely on these claims for access control. Although the user is not genuinely added to the organization, the token’s claims can grant unintended access to resources or functionalities. The vulnerability is limited to the token claim level and does not alter the actual organization membership in the backend. Admins can mitigate this by enforcing strict validation mechanisms or disabling unrestricted self-registration.
DailyCVE Form:
Platform: Keycloak
Version: >= 26.1.0, < 26.1.3; < 26.0.10
Vulnerability: Improper Authorization
Severity: Moderate
Date: Mar 10, 2025
What Undercode Say:
Exploitation:
- Craft Malicious Username/Email: Attackers create accounts with usernames or emails matching the organization’s naming pattern.
- Self-Registration Exploit: If self-registration is unrestricted, attackers register with the crafted credentials.
- Token Claim Manipulation: The attacker’s token falsely includes organization claims, misleading applications.
Protection:
- Disable Unrestricted Self-Registration: Restrict self-registration to prevent unauthorized account creation.
- Strict Validation: Implement strict validation for email/username patterns during registration.
- Update Keycloak: Upgrade to patched versions (26.1.3 or 26.0.10).
Commands:
1. Check Keycloak Version:
keycloak/bin/kc.sh --version
2. Update Keycloak:
wget https://github.com/keycloak/keycloak/releases/download/26.1.3/keycloak-26.1.3.tar.gz tar -xzf keycloak-26.1.3.tar.gz
3. Disable Self-Registration:
keycloak/bin/kc.sh --spi-registration-default-enabled=false
Code Snippets:
1. Strict Email Validation:
public boolean validateEmail(String email) {
String pattern = "^[bash]+(?:\.[bash]+)@(?:[bash]+\.)+[bash]{2,7}$";
return email.matches(pattern);
}
2. Token Claim Verification:
public boolean verifyOrganizationClaim(String token) {
DecodedJWT jwt = JWT.decode(token);
return jwt.getClaim("org").asString().equals("valid-org");
}
Analytics:
- Affected Systems: Keycloak versions 26.1.0 to 26.1.2 and versions below 26.0.10.
- Risk Level: Moderate, as it impacts token claims but not actual organization membership.
- Mitigation Adoption: Organizations using self-registration should prioritize updates and validation mechanisms.
By following these steps, organizations can effectively exploit and protect against CVE-2025-XXXX.
References:
Reported By: https://github.com/advisories/GHSA-gvgg-2r3r-53×7
Extra Source Hub:
Undercode
