Palo Alto Networks Security Advisories / CVE-2016-3657

CVE-2016-3657 Unauthenticated Buffer Overflow in GlobalProtect/SSL VPN Web Interface

047910
Severity 9.8 · CRITICAL
Attack Vector NETWORK
Attack Complexity LOW
Privileges Required NONE
User Interaction NONE
Scope UNCHANGED
Confidentiality Impact HIGH
Integrity Impact HIGH
Availability Impact HIGH

Description

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)

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.

This issue affects PAN-OS releases 5.0.17 and prior; 6.0.12 and prior; 6.1.9 and prior; 7.0.4 and prior

Product Status

VersionsAffectedUnaffected
PAN-OS 7.0<= 7.0.4>= 7.0.5
PAN-OS 6.1<= 6.1.9>= 6.1.10
PAN-OS 6.0<= 6.0.12>= 6.0.13
PAN-OS 5.0<= 5.0.17>= 5.0.18

Severity: CRITICAL

CVSSv3.1 Base Score: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness Type

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

Solution

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.

Acknowledgments

Felix Wilhelm, ERNW Research
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