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CVE-2020-2021

Palo Alto Networks — Palo Alto Networks PAN-OS Authentication Bypass Vulnerability

Palo Alto Networks · CWE-347 · in CISA KEV since 2022-03-25

ExigentKEV since 2022 · listed over a yearRansomwareCISA KEVActively Exploited
85

EVRS 85 of 100 Immediate

Out-of-Band / Urgent Remediation

Rank 450 of 2,962 tracked

Raised to the floor for a confirmed exploited vulnerability.

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Why it scores 85

Evidence available: 6 of 7 signals

Listed in the CISA KEV catalog, and associated with known ransomware campaigns.

  • CISA KEVApplied
  • RansomwareApplied
  • Vendor exploitationDid not apply
  • EPSSApplied
  • Microsoft Exploitability IndexNot applicable
  • Pre-patch disclosureNo data
  • KEV recencyDid not apply
  • CVSSApplied

The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data

Fix

Patch or fixed version identified

CISA required action

Fixed in

pan-os: update to a version newer than 8.0.20 | pan-os: update to 8.1.15 or later | pan-os: update to 9.0.9 or later | pan-os: update to 9.1.3 or later

Affected versions

  • pan-os>= 8.0.0 <= 8.0.20>= 8.1.0 < 8.1.15>= 9.0.0 < 9.0.9>= 9.1.0 < 9.1.3

Remediation

Apply updates per vendor instructions.

Fixed versions from NVD.

Evidence

Each value with its source
MeasureValueSource
CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. 10.0 NVD
FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. 0.044 (91.2nd pctl) FIRST EPSS
Actively exploitedWhether a source of record has confirmed attacks using it in the wild. Confirmed CISA KEV
Ransomware campaign useWhether CISA has seen ransomware operators use it. Known CISA KEV
CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. 2022-04-15 · KEV since 2022 · listed over a year CISA KEV
Public exploit moduleA module existing is not the same as active exploitation. None known Metasploit
EUVD cross-referenceENISA's record: CVSS 10.0 (v3.1), assigned by palo_alto. Listed ENISA EUVD

Description

NVD

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.

What CISA says to do