Unauthenticated Buffer Overflow in GlobalProtect/SSL VPN Web Interface (PAN-SA-2016-0005)

Last revised: 03/24/2016

Summary

When a PAN-OS device is configured as a GlobalProtect portal, a vulnerability exists where an improper handling of a buffer involved in the processing of SSL VPN requests can result in device crash and possible remote code execution. (Ref. #89752) (CVE-2016-3657)

Severity: Critical

An attacker with network access to the vulnerable GlobalProtect portal may be able to perform a denial-of-service (DoS) attack on the device, and may be able to perform remote code execution on the affected device.

Products Affected

PAN-OS releases 5.0.17 and prior; 6.0.12 and prior; 6.1.9 and prior; 7.0.4 and prior

Available Updates

PAN-OS releases 5.0.18 and newer; 6.0.13 and newer; 6.1.10 and newer; 7.0.5 and newer

Workarounds and Mitigations

Emergency content update 563 contains an IPS signature (#38902) that can be used as an interim mitigation to protect PAN-OS devices until the device software is upgraded. Note that signatures 38902 must be applied to a firewall rule securing traffic destined for the GlobalProtect portal. The GlobalProtect portal should only be present once per installation, limiting the organization’s exposure to this issue. This issue can be further mitigated by disabling the affected optional “login page” in the GlobalProtect portal configuration, and distribution of the client side software may be performed through alternative means such as GPO or network share while the PAN-OS patch is applied.

Acknowledgements

Felix Wilhelm, ERNW Research