CVE-2017-16855 in ipsilon
Summary
by MITRE
Ipsilon before 2.1.0 has a "SAML2 multi-session vulnerability."
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Analysis
by VulDB Data Team • 01/24/2021
The vulnerability identified as CVE-2017-16855 affects Ipsilon software versions prior to 210, specifically targeting a SAML2 multi-session vulnerability that represents a critical security flaw in identity federation implementations. This vulnerability resides within the SAML2 (Security Assertion Markup Language 2.0) protocol handling mechanisms, which are fundamental components of single sign-on (SSO) systems used across enterprise environments. The issue manifests in how the software manages multiple concurrent sessions within SAML2 environments, creating potential pathways for unauthorized access and session manipulation.
The technical flaw stems from inadequate session management controls within the Ipsilon SAML2 implementation, where the system fails to properly enforce session isolation between multiple concurrent authentication requests. This weakness allows attackers to potentially exploit session state inconsistencies, enabling them to establish unauthorized sessions or manipulate existing ones. The vulnerability specifically impacts the session tracking mechanisms that should ensure each user maintains distinct and secure session contexts. According to CWE classification, this represents a weakness in session management (CWE-613) combined with inadequate session validation (CWE-384), both of which are categorized under the broader domain of identity and access management vulnerabilities.
The operational impact of this vulnerability extends beyond simple authentication bypasses, as it can enable sophisticated attack scenarios including session hijacking, cross-site request forgery, and unauthorized privilege escalation within federated identity environments. Attackers could potentially leverage this weakness to impersonate legitimate users within SAML2 federations, particularly in scenarios where multiple applications or services share the same identity provider. The vulnerability affects organizations that rely on Ipsilon for SAML2 identity federation, potentially compromising sensitive data access and system integrity across interconnected applications. This issue aligns with ATT&CK technique T1531 (Signin Package Modification) and T1078 (Valid Accounts) as it exploits legitimate authentication mechanisms to gain unauthorized access.
Mitigation strategies for this vulnerability require immediate patching to Ipsilon versions 2.1.0 and later, which contain corrected session management implementations. Organizations should also implement enhanced monitoring of SAML2 session activities and establish strict session validation procedures to detect anomalous authentication patterns. Network segmentation and additional authentication layers can provide defense-in-depth measures while waiting for patches. Security teams should conduct thorough vulnerability assessments of their SAML2 implementations and review existing session management policies. The fix addresses the root cause by implementing proper session isolation mechanisms and strengthening the validation of session identifiers within the SAML2 protocol handling code. Additionally, organizations should review their identity federation configurations and ensure that session timeouts and renewal mechanisms are properly configured to minimize the window of opportunity for exploitation.