CVE-2019-8400 in Hydra
Summary
by MITRE
ORY Hydra before v1.0.0-rc.3+oryOS.9 has Reflected XSS via the oauth2/fallbacks/error error_hint parameter.
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Analysis
by VulDB Data Team • 07/11/2023
The vulnerability identified as CVE-2019-8400 affects ORY Hydra versions prior to v1.0.0-rc.3+oryOS.9 and represents a reflected cross-site scripting flaw within the oauth2/fallbacks/error endpoint. This issue specifically manifests through the error_hint parameter which is processed without adequate input sanitization or output encoding, creating a pathway for malicious actors to inject arbitrary JavaScript code into web responses. The vulnerability resides in the authentication and authorization framework that ORY Hydra provides, making it particularly concerning for systems relying on this component for secure identity management.
The technical implementation of this flaw involves the direct inclusion of user-supplied input from the error_hint parameter into HTTP response content without proper context-aware encoding. When an attacker crafts a malicious payload and submits it through this parameter, the web application reflects the malicious script back to the victim's browser during the error handling process. This allows attackers to execute arbitrary JavaScript code in the context of the victim's browser session, potentially leading to session hijacking, credential theft, or other malicious activities. The vulnerability is classified as a reflected XSS attack because the malicious script is reflected off the web server in response to the user's request rather than being stored on the server.
The operational impact of this vulnerability extends beyond simple script execution as it can be leveraged to bypass security controls and compromise user sessions within the ORY Hydra ecosystem. Attackers can craft sophisticated phishing campaigns that appear legitimate to users, potentially leading to unauthorized access to protected resources and sensitive data. The vulnerability affects the core authentication flow of the system, which means that any application relying on ORY Hydra for OAuth2 authentication could be compromised. The reflected nature of the vulnerability means that attackers can deliver payloads through various vectors including email links, malicious websites, or social engineering campaigns, making it particularly dangerous in real-world scenarios.
Organizations using affected versions of ORY Hydra should implement immediate mitigations including upgrading to version v1.0.0-rc.3+oryOS.9 or later where the vulnerability has been addressed. Additionally, implementing proper input validation and output encoding mechanisms for all user-supplied parameters can provide defense-in-depth protection against similar vulnerabilities. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and follows patterns commonly seen in ATT&CK technique T1059.007 for command and scripting interpreter. Security teams should also consider implementing content security policies and monitoring for suspicious parameter usage patterns to detect potential exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in the broader application ecosystem.