Source: cve@mitre.org
The H.323 protocol agent in StoneSoft firewall engine 2.2.8 and earlier allows remote attackers to cause a denial of service (crash) via crafted H.323 packets.
StoneSoft firewall engines versions 2.2.8 and earlier are vulnerable to a denial-of-service (DoS) attack via crafted H.323 packets. This vulnerability allows remote attackers to crash the firewall, potentially disrupting network services and causing significant operational impact.
Step 1: Packet Crafting: An attacker crafts a malicious H.323 packet. This packet is designed to exploit a vulnerability in the StoneSoft firewall's H.323 protocol agent. The packet likely contains malformed or unexpected data within specific fields of the H.323 protocol.
Step 2: Packet Delivery: The attacker sends the crafted H.323 packet to the StoneSoft firewall. This can be achieved by sending the packet directly to the firewall's public IP address or by routing the packet through an intermediary network.
Step 3: Packet Processing: The StoneSoft firewall's H.323 protocol agent receives and attempts to process the malicious packet.
Step 4: Vulnerability Trigger: The malformed data in the packet triggers a vulnerability within the H.323 agent. This could be a buffer overflow, an integer overflow, or an unhandled exception.
Step 5: Denial of Service: The triggered vulnerability causes the H.323 agent to crash. This crash leads to a denial of service, as the firewall engine becomes unresponsive and unable to process legitimate network traffic.
The vulnerability lies within the H.323 protocol agent's handling of malformed or unexpected H.323 packets. The specific root cause is likely a flaw in how the agent parses and processes H.323 protocol messages. This could manifest as an unhandled exception, a buffer overflow, or an integer overflow when processing specific fields within the H.323 packet. The crafted packets likely trigger a condition that leads to a crash of the firewall engine, preventing it from processing legitimate traffic.
While no specific APT groups are directly linked to this CVE, the ease of exploitation and potential impact make it attractive to various threat actors. This vulnerability could be leveraged by attackers seeking to disrupt network operations or to create a distraction for more sophisticated attacks. Not listed on CISA KEV.
Network Intrusion Detection Systems (NIDS) can be configured to detect malicious H.323 packets based on known attack signatures or anomalies in H.323 protocol traffic.
Security Information and Event Management (SIEM) systems can be used to analyze firewall logs for unusual activity, such as frequent crashes or errors related to H.323 processing.
Packet capture and analysis tools (e.g., Wireshark) can be used to examine network traffic and identify crafted H.323 packets.
Monitor firewall CPU and memory usage for sudden spikes or unusual behavior that could indicate a DoS attack.
Upgrade to a patched version of the StoneSoft firewall engine (version 2.2.9 or later).
Implement network segmentation to limit the impact of a successful attack.
Disable the H.323 protocol if it is not required for business operations. This eliminates the attack vector entirely.
Regularly monitor firewall logs for suspicious activity and unusual traffic patterns.
Implement a Web Application Firewall (WAF) to filter malicious traffic.