Authenticatoin bypass in Pan-OS GlobalProtect SSL VPN

1) Improper Authentication

EUVDB-ID: #VU48415

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-2050

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in when processing authentication requests in the GlobalProtect SSL VPN component of Palo Alto Networks PAN-OS software that allows an attacker to bypass all client certificate checks with an invalid certificate. A remote attacker can successfully authenticate as any user and gain access to restricted VPN network resources when the gateway or portal is configured to rely entirely on certificate-based authentication.

Impacted features that use SSL VPN with client certificate verification are:

GlobalProtect Gateway
GlobalProtect Portal
GlobalProtect Clientless VPN

In configurations where client certificate verification is used in conjunction with other authentication methods, the protections added by the certificate check are ignored as a result of this issue.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Palo Alto PAN-OS: 8.1 - 10.0.0

External links

http://security.paloaltonetworks.com/CVE-2020-2050

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.