CVE-2020-2021Known exploitationNetwork attack vector

Unauthenticated access via unverified SAML signatures

Published Jun 29, 2020 · Updated Oct 21, 2025

Authentication bypass in affected Palo Alto Networks PAN-OS releases allows remote attackers to access SAML-protected resources. PAN-OS accepts SAML assertions without properly verifying their cryptographic signatures when SAML is enabled and Validate Identity Provider Certificate is unchecked. Network access to an exposed service is required; affected web interfaces grant administrator access, while gateway, portal, and VPN exposure grants policy-authorized resource access without session tampering.

CVSS severity10.0
Critical
EPSS probability4.36%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in affected Palo Alto Networks PAN-OS releases allows remote attackers to access SAML-protected resources. PAN-OS accepts SAML assertions without properly verifying their cryptographic signatures when SAML is enabled and Validate Identity Provider Certificate is unchecked. Network access to an exposed service is required; affected web interfaces grant administrator access, while gateway, portal, and VPN exposure grants policy-authorized resource access without session tampering.

The record

CVE
CVE-2020-2021
Published
Jun 29, 2020
Updated
Oct 21, 2025
Vendor
Palo Alto Networks
Product
PAN-OS
Classifications
CWE-347, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.0.*
  2. Affected versionversion=8.1 <8.1.15 changes=[{"at":"8.1.15","status":"unaffected"}]
  3. Affected versionversion=9.0 <9.0.9 changes=[{"at":"9.0.9","status":"unaffected"}]
  4. Affected versionversion=9.1 <9.1.3 changes=[{"at":"9.1.3","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Palo Alto Networks · PAN-OSversion=8.0.*; version=8.1 <8.1.15 changes=[{"at":"8.1.15","status":"unaffected"}]; version=9.0 <9.0.9 changes=[{"at":"9.0.9","status":"unaffected"}]; version=9.1 <9.1.3 changes=[{"at":"9.1.3","status":"unaffected"}]

Published CVSS scores

10.0Palo Alto NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
9.6Palo Alto NetworksCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
10.0Palo Alto NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Reported exploitation

Technologies

Your stack

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Your stack

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