CVE-2016-4791 in Connect Secure
Summary
by MITRE
The administrative user interface in Pulse Connect Secure (PCS) 8.2 before 8.2r1, 8.1 before 8.1r2, 8.0 before 8.0r9, and 7.4 before 7.4r13.4 allows remote administrators to enumerate files, read arbitrary files, and conduct server side request forgery (SSRF) attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 08/22/2022
The vulnerability identified as CVE-2016-4791 affects Pulse Connect Secure (PCS) appliances running specific versions of the software, creating a critical security risk for remote administrative access. This flaw exists within the administrative user interface of the system and represents a significant weakness in the authentication and authorization mechanisms that protect enterprise network access solutions. The vulnerability allows remote attackers to exploit the administrative interface without requiring valid credentials, effectively bypassing the security controls that should protect sensitive system components.
The technical implementation of this vulnerability involves multiple attack vectors that collectively enable an attacker to perform file enumeration, arbitrary file reading, and server-side request forgery operations. The unspecified vectors suggest that the flaw stems from inadequate input validation and access control measures within the administrative interface components. Attackers can leverage this weakness to traverse the file system and access sensitive configuration files, log files, and potentially system credentials that are normally protected from unauthorized access. The server-side request forgery component allows attackers to make requests from the server on behalf of the administrative interface, potentially enabling access to internal network resources that should remain isolated from external threats.
The operational impact of this vulnerability is severe for organizations relying on Pulse Connect Secure for network access control and remote connectivity management. Remote attackers can gain unauthorized access to critical system information, potentially compromising the entire network infrastructure that the appliance protects. The ability to read arbitrary files means that attackers can extract sensitive data including encryption keys, user credentials, and system configurations that could be used for further attacks or lateral movement within the network. The SSRF capabilities extend the attack surface by allowing unauthorized access to internal systems that the appliance might be configured to communicate with, potentially exposing internal network services and resources.
Organizations affected by this vulnerability should immediately implement mitigations including applying the vendor-provided patches for all supported versions of Pulse Connect Secure. The remediation process should involve updating to the minimum recommended versions that address this vulnerability, specifically 8.2r1, 8.1r2, 8.0r9, and 7.4r13.4. Network segmentation and firewall rules should be implemented to restrict direct administrative access to the appliance from untrusted networks, limiting the attack surface for potential exploitation. The vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-918 (Server-Side Request Forgery) which categorize the issues as path traversal and server-side request forgery vulnerabilities respectively. From an ATT&CK framework perspective, this vulnerability maps to T1078 (Valid Accounts) and T1566 (Phishing) as attackers can leverage the administrative interface to gain persistent access and potentially use the compromised appliance as a pivot point for further network exploration.
The root cause of this vulnerability demonstrates inadequate security controls in the administrative interface design, specifically the lack of proper input sanitization and access validation mechanisms. This flaw represents a classic example of insufficient validation of user-supplied data and the absence of proper authorization checks before file system operations. The vulnerability's persistence across multiple major versions indicates a systemic issue in the software development lifecycle where security controls were not properly implemented or tested. Organizations should conduct comprehensive security assessments of their network access solutions and implement regular vulnerability scanning to identify similar weaknesses in their infrastructure. The exploitation of this vulnerability can lead to complete compromise of the network access control system, potentially allowing attackers to bypass all security controls that the appliance was designed to enforce, making immediate remediation critical for maintaining network security posture and compliance with industry security standards.