Horizon Alert
Summary of the vulnerability and why it matters
A misconfiguration in PAN-OS URL filtering policies can enable a network-based attacker to launch amplified denial-of-service attacks. These attacks would appear to originate from Palo Alto Networks firewalls and target a user-specified destination. Exploitation is possible if a URL filtering profile with blocked categories is applied to a source zone with an external-facing interface. This specific configuration is not typical and is likely unintended by administrators.
- PAN-OS URL filtering policies
- Policy misconfiguration allows DoS attacks
- Facilitates attacker anonymity and misdirection
Attack Path
How an attacker could exploit the issue
A network-based attacker can exploit a PAN-OS URL filtering misconfiguration to launch reflected and amplified denial-of-service attacks. These attacks appear to originate from Palo Alto Networks firewalls but target an attacker-specified destination. This could potentially obscure the attacker's identity and implicate the firewall. Exploitation of this issue does not affect the confidentiality or integrity of affected products.
- Misconfigured URL filtering policy.
- Network attacker gains access.
- Trigger DoS attack.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability allows a network-based attacker to conduct reflected and amplified denial-of-service (DoS) attacks. These attacks would appear to originate from a Palo Alto Networks firewall, potentially obfuscating the attacker's identity and implicating the firewall as the source. While the vulnerability does not impact the confidentiality or integrity of the affected products, it can lead to a denial-of-service condition for the attacker-specified target.
- Low attacker skill level.
- Requires specific firewall misconfiguration.
- High business risk due to active exploitation.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
A misconfiguration in PAN-OS URL filtering policies can allow network attackers to launch denial-of-service (DoS) attacks. These attacks appear to originate from Palo Alto Networks firewalls, potentially masking the attacker's true identity. Exploitation would not compromise data confidentiality or integrity but could disrupt service availability and implicate the firewall.
- Find firewalls with specific URL filtering misconfigurations.
- Adjust URL filtering policies to mitigate risk.
- Apply vendor updates, verify changes, and monitor.
