CVE-2016-4790 in Connect Secure
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in 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 attackers to inject arbitrary web script or HTML via unspecified vectors.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/22/2022
The CVE-2016-4790 vulnerability represents a critical cross-site scripting flaw within the administrative user interface of Pulse Connect Secure (PCS) appliances across multiple version branches. This vulnerability affects Pulse Secure's flagship product that provides secure remote access solutions for enterprise networks, making it particularly dangerous given the privileged access capabilities of the administrative interface. The flaw exists in versions 8.2 before 8.2r1, 8.1 before 8.1r2, 8.0 before 8.0r9, and 7.4 before 7.4r13.4, indicating a widespread issue that impacted a significant portion of the product's user base during that time period.
The technical nature of this vulnerability stems from insufficient input validation and output encoding within the administrative web interface of the Pulse Connect Secure appliance. Attackers can exploit this weakness by injecting malicious web scripts or HTML code through unspecified vectors that likely involve form fields, URL parameters, or other user-controllable inputs within the administrative interface. This allows remote attackers to execute arbitrary code in the context of the victim's browser, potentially compromising the administrative session and gaining unauthorized access to sensitive configuration data. The vulnerability operates under CWE-79 which classifies it as a classic cross-site scripting weakness where untrusted data is directly included in web pages without proper sanitization or encoding.
The operational impact of this vulnerability extends beyond typical XSS attacks, as it specifically targets the administrative interface of a critical network security appliance. An attacker who successfully exploits this vulnerability could potentially gain full administrative control over the Pulse Connect Secure appliance, allowing them to modify security policies, add unauthorized users, redirect traffic, or even establish persistent backdoors within the network infrastructure. This represents a severe compromise of network security posture since the administrative interface typically contains sensitive configuration information, user credentials, and network access controls. The attack vector being remote means that exploitation does not require physical access to the device, making it particularly concerning for organizations with distributed deployments or cloud-based implementations.
Organizations affected by this vulnerability should immediately implement mitigation strategies including applying the vendor-provided patches for the specific versions mentioned in the CVE. The recommended approach involves upgrading to the patched versions 8.2r1, 8.1r2, 8.0r9, and 7.4r13.4 respectively, which contain proper input validation and output encoding mechanisms. Network segmentation and access controls should be strengthened around the administrative interface, including implementing firewall rules that restrict access to administrative ports from trusted networks only. Additionally, organizations should consider implementing web application firewalls and enhanced monitoring to detect potential exploitation attempts. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1566.001 for spearphishing attachments, as attackers could leverage the compromised administrative interface to establish further footholds within the network. The security community should also consider this vulnerability as part of broader security hygiene practices, emphasizing the importance of regular patch management and input validation in web applications.