CVE-2012-0388 in IOS
Summary
by MITRE
Memory leak in the H.323 inspection feature in the Zone-Based Firewall in Cisco IOS 12.4, 15.0, 15.1, and 15.2 allows remote attackers to cause a denial of service (memory consumption or device reload) via malformed transit H.323 traffic, aka Bug ID CSCtq45553.
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability identified as CVE-2012-0388 represents a critical memory leak flaw within Cisco IOS Zone-Based Firewall implementations that affects multiple software versions including 12.4, 15.0, 15.1, and 15.2. This issue specifically targets the H.323 inspection feature which is designed to monitor and control H.323 protocol traffic for security purposes. The vulnerability operates through the inspection mechanism that processes incoming H.323 packets, particularly those that are malformed or transit through the firewall. When the firewall encounters such malformed H.323 traffic, the inspection process fails to properly release allocated memory resources, leading to progressive memory consumption over time. This memory leak directly impacts the device's operational stability and can ultimately result in complete system failure or reload.
The technical exploitation of this vulnerability occurs when remote attackers send specially crafted H.323 packets that trigger the inspection feature's memory allocation without proper deallocation. The flaw manifests in the H.323 inspection engine where memory blocks are allocated to process incoming packets but are not correctly freed when processing concludes or when malformed packets are encountered. This creates a memory leak condition that accumulates over time as the firewall continues to process traffic. The vulnerability is classified under CWE-401 as a failure to release memory resources, which is a fundamental weakness in memory management. The attack vector requires only remote access to send malformed H.323 traffic to the affected firewall, making it particularly dangerous as it can be exploited from outside the network perimeter.
The operational impact of this vulnerability extends beyond simple resource exhaustion to potentially compromise network availability and security posture. As memory consumption increases, the firewall may experience performance degradation, reduced capacity to process legitimate traffic, and eventually complete system instability requiring manual intervention or automatic device reloads. This denial of service condition effectively disables the firewall's ability to protect network traffic, creating a security gap where malicious actors can bypass firewall protections. The vulnerability affects the core functionality of the Zone-Based Firewall, which is designed to provide network segmentation and traffic control, rendering the security boundary ineffective. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 (Endpoint Denial of Service) and T1566.002 (Phishing with Malicious Attachments) as it can be leveraged to disrupt network services and potentially facilitate further attacks through service disruption.
Cisco has addressed this vulnerability through software updates and patches that correct the memory management issue in the H.323 inspection feature. Organizations should implement the latest IOS patches available for their affected software versions to remediate the vulnerability. Network administrators should also consider disabling H.323 inspection features if the protocol is not actively required, as this provides an additional mitigation layer. Monitoring for unusual memory consumption patterns and implementing intrusion detection systems that can identify malformed H.323 traffic can help detect exploitation attempts. The vulnerability demonstrates the importance of proper memory management in network security devices and the critical need for regular security updates to address such fundamental flaws that can lead to complete system compromise.