dbcve.org
Pan OsOperating system · Paloaltonetworks

CVE-2020-2040

CRITICAL · 9.8 CVSS v3.1 Published 2020-09-09
Fix available
A fix is available. Upgrade to 8.1.15 / 9.0.9 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A buffer overflow vulnerability in PAN-OS allows an unauthenticated attacker to disrupt system processes and potentially execute arbitrary code with root privileges by sending a malicious request to the Captive Portal or Multi-Factor Authentication interface. This issue impacts: All versions of PAN-OS 8.0; PAN-OS 8.1 versions earlier than PAN-OS 8.1.15; PAN-OS 9.0 versions earlier than PAN-OS 9.0.9; PAN-OS 9.1 versions earlier than PAN-OS 9.1.3.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A buffer overflow vulnerability in Palo Alto Networks PAN-OS allows unauthenticated attackers to send malicious requests to the Captive Portal or Multi-Factor Authentication interface, potentially executing arbitrary code with root privileges. The vulnerability affects multiple PAN-OS versions across 8.0, 8.1, 9.0, and 9.1 branches.

MitigationUpgrade PAN-OS to version 8.1.15 or later (8.1 branch), 9.0.9 or later (9.0 branch), 9.1.3 or later (9.1 branch), or a later supported version. For 8.0, upgrade to a supported branch as 8.0 is end-of-life.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Pan OsOperating system
Affected:>= 8.0.0, <= 8.0.20>= 8.1.0, < 8.1.15>= 9.0.0, < 9.0.9>= 9.1.0, < 9.1.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine PAN-OS version
    Check the installed PAN-OS version via CLI command 'show system info' or through the web management interface under Device > Support
    Affected if The installed version falls within any of these ranges: 8.0.0 to 8.0.20, 8.1.0 to 8.1.14, 9.0.0 to 9.0.8, or 9.1.0 to 9.1.2
  2. Verify Captive Portal status
    Check if Captive Portal is enabled on the device through the web interface under Network > Captive Portal or via CLI command 'show captive-portal'
    Affected if Captive Portal is enabled and the PAN-OS version is in any of the affected ranges listed above
  3. Verify Multi-Factor Authentication status
    Check if Multi-Factor Authentication (MFA) is configured and active on the device through the web interface under Device > User Identification > Multi-Factor Authentication or via appropriate CLI commands
    Affected if MFA is enabled and the PAN-OS version is in any of the affected ranges listed above

If the PAN-OS version falls within any affected range AND either Captive Portal or Multi-Factor Authentication is enabled, the environment is vulnerable to CVE-2020-2040.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.1.15 / 9.0.9 / 9.1.3 or later
Fixed in 8.1.159.0.99.1.3
Interim mitigation

Upgrade PAN-OS to version 8.1.15 or later (8.1 branch), 9.0.9 or later (9.0 branch), 9.1.3 or later (9.1 branch), or a later supported version. For 8.0, upgrade to a supported branch as 8.0 is end-of-life.

Recommended fix High confidence

PAN-OS 8.1.15+ (or 9.0.9+ or 9.1.3+ depending on target branch); PAN-OS 8.0.x has no fix and requires migration to 8.1.15+

  1. Identify the current PAN-OS version running on the firewall by navigating to Device > Setup > Operations or using 'show system info' in the CLI
  2. Determine which version branch (8.0, 8.1, 9.0, or 9.1) is currently in use
  3. For PAN-OS 8.0.x systems: Upgrade to PAN-OS 8.1.15 or later (note: 8.0.x has no fixed release, migration to a newer branch is required)
  4. For PAN-OS 8.1.x systems: Upgrade to PAN-OS 8.1.15 or later
  5. For PAN-OS 9.0.x systems: Upgrade to PAN-OS 9.0.9 or later
  6. For PAN-OS 9.1.x systems: Upgrade to PAN-OS 9.1.3 or later
  7. Download the appropriate PAN-OS upgrade file from the Palo Alto Networks Support Portal
  8. Upload the update via Panorama (if managed) or directly to the firewall via Device > Software or 'request system software add' CLI command
Caveat Review Palo Alto Networks Upgrade Guide for compatibility notes; PAN-OS 8.0.x has no patch and requires migration to 8.1+ which may have configuration or feature changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Pan Os Scoped from the published advisory
  • Consultation6.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,660
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,856.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-2040 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-2040 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data