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NVD / CVE Program· CNA palo_alto

CVE-2020-2021: PAN-OS: Authentication Bypass in SAML Authentication

CriticalCVSS 10.0 · v3.1KEVWeaponized Fix available

Noroxi assessment

Priority: This week (action score 71/100)

  • CISA has confirmed exploitation in the wild (Mar 25, 2022); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Apr 15, 2022.
  • Probability of exploitation in the next 30 days: 4.3% (FIRST EPSS); higher than 91.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Palo Alto Networks PAN-OS 8.1.15, 9.0.9, 9.1.3.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Don’t wait for the next maintenance window. Upgrade to Palo Alto Networks PAN-OS 8.1.15, 9.0.9, 9.1.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

Published
Jun 29, 2020
Updated
Jun 16, 2026
EPSS
4.3% · 91th percentile

Report tools

JSON

Action score

71

This week

Don’t wait for the next maintenance window.

CVSS
40 / 40 · 10.0 / 10
CISA KEV
30 / 30 · Listed
EPSS
1 / 30 · 4.3%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
10.0
CNA · palo_alto
10.0
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Mar 25, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Apr 15, 2022.

Known to be used in ransomware campaigns.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2020-2021

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
paloaltonetworkspan-os

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When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

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Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every Monday

Versions reported by the vendor

Affected version ranges reported by the assigning authority (palo_alto). Independent of NVD's CPE analysis and usually ahead of it.

  • Palo Alto Networks PAN-OS

    • 8.0.*affected
    • 7.1.*not affected
    • 8.1 and later · before 8.1.15affectedfixed in 8.1.15
    • 9.0 and later · before 9.0.9affectedfixed in 9.0.9
    • 9.1 and later · before 9.1.3affectedfixed in 9.1.3
Affected versions · NVD (4)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • paloaltonetworks pan-os8.0.0 and later · up to 8.0.20 inclusive
  • paloaltonetworks pan-os8.1.0 and later · before 8.1.15
  • paloaltonetworks pan-os9.0.0 and later · before 9.0.9
  • paloaltonetworks pan-os9.1.0 and later · before 9.1.3

Same product

paloaltonetworks: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-3400PAN-OS: Arbitrary File Creation Leads to OS Command Injection Vulnerability in GlobalProtectKEV
    100Now
  • CVE-2017-15944Palo Alto Networks PAN-OS before 6.1.19, 7.0.x before 7.0.19, 7.1.x before 7.1.14, and 8.0.x before 8.0.6 allows remote attackers to…KEV
    99Now
  • CVE-2024-0012PAN-OS: Authentication Bypass in the Management Web Interface (PAN-SA-2024-0015)KEV
    97Now

Published before and after this one in the same product

  • ← EarlierCVE-2020-2028Jun 10, 2020 · PAN-OS: OS command injection vulnerability in FIPS-CC mode certificate verification
    29Monitor
  • ← EarlierCVE-2020-2029Jun 10, 2020 · PAN-OS: OS command injection vulnerability in management interface certificate generator
    29Monitor
  • Later →CVE-2020-1982Jul 8, 2020 · PAN-OS: TLS 1.0 usage for certain communications with Palo Alto Networks cloud delivered services
    19Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Palo Alto Networks PAN-OS8.1.15Vendor (CNA)
Palo Alto Networks PAN-OS9.0.9Vendor (CNA)
Palo Alto Networks PAN-OS9.1.3Vendor (CNA)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-09-05

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. CISA KEV+634 d
  3. First PoC+2259 d
  4. TodayNov 14, 2026+2329 d

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-347 · Improper Verification of Cryptographic Signature

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

nvd-primary

Root cause

The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.

The bug in code

The whole CWE-347 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const claims = jwt.verify(token, publicKey);

Fixed

ts
const claims = jwt.verify(token, publicKey, {  algorithms: ["RS256"],  issuer: "https://id.example.com",  audience: "portal",});

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records