CVE-2012-0383 in IOS
Summary
by MITRE
Memory leak in the NAT feature in Cisco IOS 12.4, 15.0, and 15.1 allows remote attackers to cause a denial of service (memory consumption, and device hang or reload) via SIP packets that require translation, related to a "memory starvation vulnerability," aka Bug ID CSCti35326.
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability described in CVE-2012-0383 represents a critical memory management flaw within Cisco IOS operating systems affecting versions 12.4, 15.0, and 15.1. This issue specifically targets the Network Address Translation (NAT) functionality that processes Session Initiation Protocol (SIP) packets requiring translation. The flaw manifests as a memory leak condition that occurs when the system processes certain SIP packets that necessitate NAT traversal, creating a persistent degradation of system resources. The vulnerability operates at the kernel level within the IOS networking stack, where improper memory allocation and deallocation routines fail to properly release memory segments after processing translated SIP traffic.
The technical implementation of this vulnerability stems from inadequate memory management within the NAT processing module when handling SIP packet translation requests. When SIP packets requiring NAT translation are received, the system allocates memory resources to process the translation but fails to consistently release these resources upon completion of the translation process. This results in a progressive accumulation of unreleased memory segments within the device's memory pool, leading to memory starvation conditions that ultimately cause system instability. The flaw is particularly insidious because it operates silently during normal operation, gradually consuming available memory until system resources are exhausted, at which point the device experiences either a complete hang or automatic reload to recover from the memory exhaustion state.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential network-wide consequences when deployed at scale. Remote attackers can exploit this vulnerability by sending specifically crafted SIP packets to targeted Cisco IOS devices configured with NAT functionality, particularly those serving as SIP gateways or proxies. The attack requires minimal privileges and can be executed from any network location capable of reaching the vulnerable device, making it highly attractive to malicious actors seeking to disrupt communications services. The memory starvation effect can occur gradually over time, allowing attackers to maintain persistent disruption without detection, or rapidly consume resources to cause immediate device unavailability. This vulnerability directly maps to CWE-401: Improper Release of Memory and aligns with ATT&CK technique T1499.004: Endpoint Denial of Service, specifically targeting network infrastructure devices.
Mitigation strategies for this vulnerability require immediate implementation of Cisco's recommended security patches and updates to address the underlying memory management flaws in the NAT processing module. Network administrators should prioritize patching affected devices, particularly those serving as SIP translation points or acting as gateways between different network segments. Configuration modifications can include implementing rate limiting on SIP traffic, disabling NAT for SIP traffic where possible, and deploying additional monitoring to detect memory consumption patterns that may indicate exploitation attempts. The vulnerability also highlights the importance of network segmentation and implementing proper access controls to limit exposure of vulnerable devices to untrusted networks, while maintaining compliance with security frameworks such as NIST SP 800-53 controls for system and information integrity. Organizations should also consider implementing intrusion detection systems capable of identifying anomalous SIP traffic patterns that may indicate exploitation attempts targeting this specific vulnerability.