CVE-2016-3657 in PAN-OS
Summary
by MITRE
Buffer overflow in the GlobalProtect Portal in Palo Alto Networks PAN-OS before 5.0.18, 6.0.x before 6.0.13, 6.1.x before 6.1.10, and 7.0.x before 7.0.5 allows remote attackers to cause a denial of service (device crash) or possibly execute arbitrary code via an SSL VPN request.
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Analysis
by VulDB Data Team • 07/24/2022
The vulnerability identified as CVE-2016-3657 represents a critical buffer overflow flaw within the GlobalProtect Portal component of Palo Alto Networks PAN-OS operating systems. This security weakness affects multiple version ranges including pre-5.0.18, pre-6.0.13, pre-6.1.10, and pre-7.0.5 releases, creating a significant exposure across the vendor's product lineage. The buffer overflow occurs during processing of SSL VPN requests, making it particularly dangerous as it can be exploited by remote attackers without requiring authentication or physical access to the network infrastructure.
The technical nature of this vulnerability stems from improper input validation within the GlobalProtect Portal's SSL VPN handling mechanism. When processing incoming SSL VPN requests, the system fails to properly bounds-check data buffers, allowing maliciously crafted input to overwrite adjacent memory locations. This classic buffer overflow condition can result in unpredictable behavior including application crashes, system instability, and potentially complete device compromise. The flaw operates at the network protocol level where untrusted input flows through the SSL VPN tunnel, making it accessible to attackers positioned anywhere on the network path between client and server.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable remote code execution capabilities. Attackers exploiting this flaw could gain unauthorized access to network infrastructure, escalate privileges, and establish persistent access points within protected environments. The GlobalProtect Portal serves as a critical gateway for remote access to corporate networks, making this vulnerability particularly attractive to threat actors seeking to breach enterprise security perimeters. Organizations relying on Palo Alto Networks firewalls for SSL VPN services face significant risk of unauthorized network access, data exfiltration, and lateral movement within their infrastructure.
Mitigation strategies for CVE-2016-3657 require immediate implementation of vendor-provided security patches and updates to affected PAN-OS versions. Organizations should prioritize updating to the latest supported releases that contain fixes for this buffer overflow vulnerability. Network administrators should also implement additional monitoring and detection measures to identify potential exploitation attempts, including analyzing SSL VPN traffic patterns and monitoring for unusual connection behavior. The vulnerability aligns with CWE-121, which categorizes buffer overflow conditions as a fundamental weakness in software design, and maps to ATT&CK technique T1071.004 for application layer protocol usage in network communications. Security teams should conduct comprehensive vulnerability assessments to identify all affected devices and implement network segmentation to limit the potential impact of successful exploitation attempts.