CVE-2020-8243 in Pulse Connect Secure
Summary
by MITRE • 10/04/2020
A vulnerability in the Pulse Connect Secure < 9.1R8.2 admin web interface could allow an authenticated attacker to upload custom template to perform an arbitrary code execution.
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Analysis
by VulDB Data Team • 12/17/2025
The vulnerability identified as CVE-2020-8243 resides within the Pulse Connect Secure administrative web interface version 9.1R8.2 and earlier, representing a critical security flaw that enables authenticated attackers to escalate their privileges through arbitrary code execution. This issue stems from insufficient input validation and inadequate restrictions on file upload functionalities within the administrative portal, creating a pathway for malicious actors who have already gained access to legitimate credentials to execute unauthorized commands on the affected system.
The technical implementation of this vulnerability involves a flawed file upload mechanism that fails to properly validate the content and type of files being uploaded to the server. When an authenticated user attempts to upload a custom template file through the administrative interface, the system does not adequately verify the file's integrity or enforce strict type checking. This weakness allows an attacker to upload a malicious file that can be executed with the privileges of the web application, potentially leading to complete system compromise. The vulnerability is classified under CWE-434 as Unrestricted Upload of File with Dangerous Type, which specifically addresses the risks associated with allowing users to upload files without proper validation mechanisms.
The operational impact of CVE-2020-8243 extends beyond simple privilege escalation, as it provides attackers with the capability to execute arbitrary code on the Pulse Connect Secure appliance. This execution capability can be leveraged to establish persistent backdoors, exfiltrate sensitive data, or further compromise the network infrastructure. The attack requires only legitimate administrative credentials, making it particularly dangerous as it can be executed by insiders or compromised accounts. The vulnerability affects organizations that rely on Pulse Connect Secure for remote access and VPN services, potentially exposing critical network resources to unauthorized access and data breaches.
Organizations affected by this vulnerability should immediately implement mitigations including patching to version 9.1R8.2 or later, which includes proper input validation and file type restrictions. Additional defensive measures should encompass network segmentation to limit access to the administrative interface, implementing strict access controls and monitoring for unusual upload activities. The mitigation strategy aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, as the vulnerability enables attackers to execute commands through the compromised web interface. Security teams should also consider implementing web application firewalls to monitor and block suspicious file upload patterns, and conduct regular security assessments to identify similar vulnerabilities in other administrative interfaces. Organizations should prioritize credential security through multi-factor authentication and regular access reviews to minimize the risk of unauthorized access to administrative portals.