CVE Catalog

Actively exploited in the wild

Palo Alto Networks PAN-OS Authentication Bypass Vulnerability

Palo Alto Networks - PAN-OS · Listed in the CISA KEV since 2022-03-25. This indicates confirmed attacks in production environments.

Required action: Apply updates per vendor instructions.

CVE-2020-2021

CriticalCVSS 10.0KEV
Published: Updated: Translated: NVD NIST

Summary

A vulnerability in PAN-OS SAML authentication due to improper signature verification when the 'Validate Identity Provider Certificate' option is disabled. An unauthenticated network-based attacker can access protected resources, and for PAN-OS/Panorama web interfaces, can log in as an administrator. Affects PAN-OS 9.1 < 9.1.3, 9.0 < 9.0.9, 8.1 < 8.1.15, and all 8.0 versions (EOL).

Risk Assessment

In the worst case (web interfaces), an attacker can gain administrative control over the device, posing a critical risk to the organization. If web interfaces are restricted to a management network, the risk is slightly lower but still high.

Recommendation

Immediately upgrade PAN-OS to version 9.1.3, 9.0.9, or 8.1.15 (or later). If upgrade is not possible, enable the 'Validate Identity Provider Certificate' option in the SAML Identity Provider Server Profile or restrict network access to management interfaces.

Other vulnerabilities in PAN-OS

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Original NVD description (English source)

When Security Assertion Markup Language (SAML) authentication is enabled and the 'Validate Identity Provider Certificate' option is disabled (unchecked), improper verification of signatures in PAN-OS SAML authentication enables an unauthenticated network-based attacker to access protected resources. The attacker must have network access to the vulnerable server to exploit this vulnerability. This issue affects PAN-OS 9.1 versions earlier than PAN-OS 9.1.3; PAN-OS 9.0 versions earlier than PAN-OS 9.0.9; PAN-OS 8.1 versions earlier than PAN-OS 8.1.15, and all versions of PAN-OS 8.0 (EOL). This issue does not affect PAN-OS 7.1. This issue cannot be exploited if SAML is not used for authentication. This issue cannot be exploited if the 'Validate Identity Provider Certificate' option is enabled (checked) in the SAML Identity Provider Server Profile. Resources that can be protected by SAML-based single sign-on (SSO) authentication are: GlobalProtect Gateway, GlobalProtect Portal, GlobalProtect Clientless VPN, Authentication and Captive Portal, PAN-OS next-generation firewalls (PA-Series, VM-Series) and Panorama web interfaces, Prisma Access In the case of GlobalProtect Gateways, GlobalProtect Portal, Clientless VPN, Captive Portal, and Prisma Access, an unauthenticated attacker with network access to the affected servers can gain access to protected resources if allowed by configured authentication and Security policies. There is no impact on the integrity and availability of the gateway, portal or VPN server. An attacker cannot inspect or tamper with sessions of regular users. In the worst case, this is a critical severity vulnerability with a CVSS Base Score of 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N). In the case of PAN-OS and Panorama web interfaces, this issue allows an unauthenticated attacker with network access to the PAN-OS or Panorama web interfaces to log in as an administrator and perform administrative actions. In the worst-case scenario, this is a critical severity vulnerability with a CVSS Base Score of 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). If the web interfaces are only accessible to a restricted management network, then the issue is lowered to a CVSS Base Score of 9.6 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). Palo Alto Networks is not aware of any malicious attempts to exploit this vulnerability.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS