CVE-2017-10873 in OpenAM
Summary
by MITRE
OpenAM (Open Source Edition) allows an attacker to bypass authentication and access unauthorized contents via unspecified vectors. Note that this vulnerability affects OpenAM (Open Source Edition) implementations configured as SAML 2.0IdP, and switches authentication methods based on AuthnContext requests sent from the service provider.
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Analysis
by VulDB Data Team • 12/02/2019
The vulnerability identified as CVE-2017-10873 represents a critical authentication bypass flaw within OpenAM versions configured as SAML 2.0 Identity Providers. This weakness specifically targets the authentication flow mechanism that relies on AuthnContext requests from service providers to determine appropriate authentication methods. The vulnerability enables unauthorized access to protected resources by allowing attackers to manipulate the authentication context switching process without proper authorization. The flaw manifests when OpenAM processes authentication requests that contain specific AuthnContext values, potentially causing the system to incorrectly evaluate authentication requirements and grant access to privileged content.
The technical implementation of this vulnerability stems from insufficient validation of authentication context requests within the SAML 2.0 Identity Provider framework. When service providers send AuthnContext requests to OpenAM, the system should rigorously verify the legitimacy and authorization scope of these requests before switching authentication methods. However, the vulnerability allows attackers to craft malicious AuthnContext values that bypass these validation checks, effectively tricking the OpenAM system into accepting weaker authentication methods or skipping authentication entirely. This represents a fundamental flaw in the authentication flow control mechanism, where the system fails to properly enforce security policies based on the received authentication context information.
The operational impact of CVE-2017-10873 extends beyond simple unauthorized access to encompass potential data breaches and privilege escalation scenarios. Attackers leveraging this vulnerability can gain access to sensitive user information, administrative functions, and confidential data stored within OpenAM-protected environments. The vulnerability affects organizations using OpenAM as their primary identity management solution, particularly those implementing SAML 2.0 federation protocols. The attack vector is particularly concerning because it operates at the authentication layer, meaning that successful exploitation can compromise the entire identity management infrastructure without requiring additional credentials or access points.
Organizations affected by this vulnerability should prioritize immediate remediation through official OpenAM patches and updates released by ForgeRock. The mitigation strategy should include comprehensive testing of authentication flows to ensure that all AuthnContext requests are properly validated before authentication method switching occurs. Security teams must implement monitoring solutions to detect anomalous authentication context requests that could indicate exploitation attempts. Additionally, organizations should consider implementing network segmentation and access controls to limit the potential impact of successful exploitation, as the vulnerability affects the core authentication mechanism rather than specific application components. This vulnerability aligns with CWE-287 which addresses improper handling of authentication context, and maps to ATT&CK technique T1078 which covers valid accounts and legitimate credentials abuse. The attack surface is particularly wide given that OpenAM is commonly deployed in enterprise environments where SAML 2.0 federation is extensively used for single sign-on and identity federation scenarios.