Palo Alto PAN-OS URL Filtering Misconfig Enables RDoS Attack
CVE-2022-0028 Published on August 10, 2022

PAN-OS: Reflected Amplification Denial-of-Service (DoS) Vulnerability in URL Filtering
A PAN-OS URL filtering policy misconfiguration could allow a network-based attacker to conduct reflected and amplified TCP denial-of-service (RDoS) attacks. The DoS attack would appear to originate from a Palo Alto Networks PA-Series (hardware), VM-Series (virtual) and CN-Series (container) firewall against an attacker-specified target. To be misused by an external attacker, the firewall configuration must have a URL filtering profile with one or more blocked categories assigned to a source zone that has an external facing interface. This configuration is not typical for URL filtering and, if set, is likely unintended by the administrator. If exploited, this issue would not impact the confidentiality, integrity, or availability of our products. However, the resulting denial-of-service (DoS) attack may help obfuscate the identity of the attacker and implicate the firewall as the source of the attack. We have taken prompt action to address this issue in our PAN-OS software. All software updates for this issue are expected to be released no later than the week of August 15, 2022. This issue does not impact Panorama M-Series or Panorama virtual appliances. This issue has been resolved for all Cloud NGFW and Prisma Access customers and no additional action is required from them.

NVD

Known Exploited Vulnerability

This Palo Alto Networks PAN-OS Reflected Amplification Denial-of-Service Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. A Palo Alto Networks PAN-OS URL filtering policy misconfiguration could allow a network-based attacker to conduct reflected and amplified TCP denial-of-service (RDoS) attacks.

The following remediation steps are recommended / required by September 12, 2022: Apply updates per vendor instructions.

Vulnerability Analysis

CVE-2022-0028 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Timeline

Initial publication

Weakness Type

What is a Network Amplification Vulnerability?

The software does not sufficiently monitor or control transmitted network traffic volume, so that an actor can cause the software to transmit more traffic than should be allowed for that actor. In the absence of a policy to restrict asymmetric resource consumption, the application or system cannot distinguish between legitimate transmissions and traffic intended to serve as an amplifying attack on target systems. Systems can often be configured to restrict the amount of traffic sent out on behalf of a client, based on the client's origin or access level. This is usually defined in a resource allocation policy. In the absence of a mechanism to keep track of transmissions, the system or application can be easily abused to transmit asymmetrically greater traffic than the request or client should be permitted to.

CVE-2022-0028 has been classified to as a Network Amplification vulnerability or weakness.


Products Associated with CVE-2022-0028

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Palo Alto Networks PAN-OS
 

Affected Versions

Palo Alto Networks Cloud NGFW: Palo Alto Networks PAN-OS: Palo Alto Networks Prisma Access: paloaltonetworks pan-os: paloaltonetworks pan-os: paloaltonetworks pan-os: paloaltonetworks pan-os: paloaltonetworks pan-os: paloaltonetworks pan-os:

Exploit Probability

EPSS
4.68%
Percentile
89.20%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.