Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

CVE-2020-2040: Critical Buffer Overflow Vulnerability in PAN-OS Devices Disclosed

PAN-OS devices that have enabled the captive portal or multi-factor authentication features are vulnerable to a critical buffer overflow flaw.

Background

On September 9, Palo Alto Networks (PAN) published nine security advisories for a series of vulnerabilities affecting PAN-OS, a custom operating system (OS) found in PAN’s next-generation firewalls. Of the nine security advisories, only one is rated critical.

Analysis

CVE-2020-2040 is a critical buffer overflow vulnerability in PAN-OS when either the Captive Portal or Multi-Factor Authentication (MFA) feature has been enabled. According to PAN’s advisory, a remote, unauthenticated attacker could exploit this vulnerability by sending a malicious request to a vulnerable PAN-OS device when one of these features is enabled. Successful exploitation of this vulnerability could result in the disruption of system processes, as well as allow arbitrary code execution on the PAN-OS devices with root privileges. The vulnerability received a critical CVSSv3 score of 9.8.

PAN explicitly states that GlobalProtect VPN and the PAN-OS management web interfaces are not affected by CVE-2020-2040.

Second Critical PAN-OS vulnerability in three months

This is the second critical vulnerability in PAN-OS devices that has been patched in the last three months. In July, PAN published a security advisory for CVE-2020-2021, another critical PAN-OS flaw that received the highest possible CVSSv3 score of 10.0.

Thousands of PAN-OS devices publicly accessible

A search via Shodan shows that there are over 14,000 PAN-OS devices that are publicly accessible. However, it is unclear how many of the 14,000 PAN-OS devices are indeed vulnerable.

Additional PAN-OS vulnerabilities patched

In addition to CVE-2020-2040, PAN released the following eight security advisories for vulnerabilities in PAN-OS:

CVE Vulnerability Type CVSSv3 Advisory
CVE-2020-2036 Reflected Cross-Site Scripting (XSS) 8.8 PAN-116720
CVE-2020-2041 Denial of Service (DoS) 7.5 PAN-151978
CVE-2020-2037 OS Command Injection 7.2 PAN-128761
CVE-2020-2038 OS Command Injection 7.2 PAN-101484
CVE-2020-2042 Buffer Overflow 7.2 PAN-145797 and PAN-150409
CVE-2020-2039 Denial of Service (DoS) 5.3 PAN-148806
CVE-2020-2043 Cleartext Storage of Sensitive Information 3.3 PAN-146837
CVE-2020-2044 Cleartext Storage of Sensitive Information 3.3 PAN-135262

Proof of concept

At the time this blog post was published, there was no proof-of-concept (PoC) code for CVE-2020-2040. Because this vulnerability was discovered through an internal security review, a PoC is not expected to be published anytime soon. However, as researchers investigate this vulnerability further, some type of PoC may be released. If and when that changes, we will provide an update.

Solution

PAN released patches to address this vulnerability for the following PAN-OS releases:

PAN-OS Version Affected Versions Fixed Versions
10.0 Not Affected -
9.1 9.1.2 and below 9.1.3 and greater
9.0 9.0.8 and below 9.0.9 and greater
8.1 8.1.14 and below 8.1.15 and greater
8.0 All versions None, please upgrade

PAN notes that all versions of PAN-OS version 8.0 are affected and the only solution to address this vulnerability is to upgrade to another fixed version outside of the 8.0 branch. Additionally, PAN-OS devices running version 10.0 are not affected by this vulnerability.

Identifying affected systems

A list of Tenable plugins to identify this vulnerability will appear here as they’re released.

Get more information

Join Tenable's Security Response Team on the Tenable Community.

Learn more about Tenable, the first Cyber Exposure platform for holistic management of your modern attack surface.

Get a free 30-day trial of Tenable.io Vulnerability Management.

Subscribe to the Tenable Blog

Subscribe
Try for Free Buy Now

Try Tenable.io

FREE FOR 30 DAYS

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Sign up now.

Buy Tenable.io

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Purchase your annual subscription today.

65 assets

Choose Your Subscription Option:

Buy Now
Try for Free Buy Now

Try Nessus Professional Free

FREE FOR 7 DAYS

Nessus® is the most comprehensive vulnerability scanner on the market today. Nessus Professional will help automate the vulnerability scanning process, save time in your compliance cycles and allow you to engage your IT team.

Buy Nessus Professional

Nessus® is the most comprehensive vulnerability scanner on the market today. Nessus Professional will help automate the vulnerability scanning process, save time in your compliance cycles and allow you to engage your IT team.

Buy a multi-year license and save. Add Advanced Support for access to phone, community and chat support 24 hours a day, 365 days a year. Full details here.

Try for Free Buy Now

Try Tenable.io Web Application Scanning

FREE FOR 30 DAYS

Enjoy full access to our latest web application scanning offering designed for modern applications as part of the Tenable.io platform. Safely scan your entire online portfolio for vulnerabilities with a high degree of accuracy without heavy manual effort or disruption to critical web applications. Sign up now.

Buy Tenable.io Web Application Scanning

Enjoy full access to a modern, cloud-based vulnerability management platform that enables you to see and track all of your assets with unmatched accuracy. Purchase your annual subscription today.

5 FQDNs

$3,578

Buy Now

Try for Free Contact Sales

Try Tenable.io Container Security

FREE FOR 30 DAYS

Enjoy full access to the only container security offering integrated into a vulnerability management platform. Monitor container images for vulnerabilities, malware and policy violations. Integrate with continuous integration and continuous deployment (CI/CD) systems to support DevOps practices, strengthen security and support enterprise policy compliance.

Buy Tenable.io Container Security

Tenable.io Container Security seamlessly and securely enables DevOps processes by providing visibility into the security of container images – including vulnerabilities, malware and policy violations – through integration with the build process.

Get a Demo of Tenable.sc

Please fill out the form below with your contact information and a sales representative will contact you shortly to schedule a demo. You may also include a short comment (limited to 255 characters). Please note that fields with asterisks (*) are mandatory.

Try for Free Contact Sales

Try Tenable Lumin

FREE FOR 30 DAYS

Visualize and explore your Cyber Exposure, track risk reduction over time and benchmark against your peers with Tenable Lumin.

Buy Tenable Lumin

Contact a Sales Representative to see how Lumin can help you gain insight across your entire organization and manage cyber risk.

Request a demo of Tenable.ot

Get the Operational Technology Security You Need.
Reduce the Risk You Don’t.