IT Pro is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more

Hackers primed to exploit CVSS 10-rated flaw in Palo Alto's PAN-OS

The SAML-based authentication flaw in the firm’s networking services allows an attacker to gain access to assets

US Cyber Command has urged Palo Alto customers to their patch PAN-OS networking systems before cyber criminals have the opportunity to exploit a highly critical authentication vulnerability.

Assigned a rare CVSS score of 10/10, the flaw dubbed CVE-2020-2021 can allow an attacker to bypass authentication procedures and access a device without needing to provide credentials.

The vulnerability is triggered when the Security Assertion Markup Language (SAML) is enabled and the ‘validate identity provider certificate’ option is disabled. This causes the improper verification of signatures in PAN-OS, allowing an attacker with network access to the vulnerable server to access protected resources. 

“Please patch all devices affected by CVE-2020-2021 immediately, especially if SAML is in use,” US Cyber Command has tweeted. “Foreign APTs will likely attempt exploit soon. We appreciate Palo Alto Networks’ proactive response to this vulnerability.”

PAN-OS is the software that runs all Palo Alto firewalls, offering customers complete visibility and control of the apps in use by all users in all locations across an enterprise network. 

The flaw, which has been fixed, 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, which has reached end-of-life. 

Moreover, the flaw can only be exploited if SAML is in use for authentication. Elements of PAN-OS overseen by SAML-based authentication include virtual private network (VPN), GlobalProtect Gateways, GlobalProtect Portal, Captive Portal and Prisma Access. 

Vulnerabilities assigned a 10/10 rating on the CVSS scale are rare, and normally mean the exploit is highly exploitable, easy to trigger, and require little or no additional privileges and user interaction.

Related Resource

Putting a spotlight on cyber security

An examination of the current cyber security landscape

Download now

Nevertheless, the company has not yet seen evidence of active exploitation in the wild, despite warnings from US Cyber Command of imminent attempts by foreign APTs

Palo Alto has urged customers to ensure the signing certificate for their SAML Identity Provider is configured as the ‘Identity Provider Certificate’ before they upgrade to a fixed version of PAN-OS.

As short-term mitigation, restarting firewalls and the Panorama web interface eliminates any unauthorised sessions on the web interface. 

For evidence of a compromise, the company has urged customers to examine Authentication Logs, User-ID Logs, ACC NEtwork Activity Source/Destination Regions, Customers Reports, and GlobalProtect Logs in PAN-OS 9.1.0 and above.

Featured Resources

Join the 90% of enterprises accelerating to the cloud

Business transformation through digital modernisation

Free Download

Delivering on demand: Momentum builds toward flexible IT

A modern digital workplace strategy

Free download

Modernise the workforce experience

Actionable insights and an optimised experience for both IT and end users

Free Download

The digital workplace roadmap

A leader's guide to strategy and success

Free Download

Most Popular

Universities are fighting a cyber security war on multiple fronts
cyber security

Universities are fighting a cyber security war on multiple fronts

4 Jul 2022
Hackers claim to steal personal data of over a billion people in China
data breaches

Hackers claim to steal personal data of over a billion people in China

4 Jul 2022
Latest LockBit ransomware strain 'strikingly similar' to BlackMatter
ransomware

Latest LockBit ransomware strain 'strikingly similar' to BlackMatter

4 Jul 2022