CVE-2010-4683 in IOS
Summary
by MITRE
Memory leak in Cisco IOS before 15.0(1)XA5 might allow remote attackers to cause a denial of service (memory consumption) by sending a crafted SIP REGISTER message over UDP, aka Bug ID CSCtg41733.
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Analysis
by VulDB Data Team • 10/11/2021
The vulnerability identified as CVE-2010-4683 represents a critical memory leak issue within Cisco IOS software versions prior to 15.0(1)XA5. This flaw specifically affects the Session Initiation Protocol implementation within Cisco routers and switches, creating a significant security risk that can be exploited remotely. The vulnerability manifests when the system processes a specially crafted SIP REGISTER message transmitted over the User Datagram Protocol, which is commonly used for VoIP communication and session management in enterprise networks. The memory leak occurs during the processing of these malformed SIP messages, leading to progressive memory consumption that can eventually exhaust available system resources.
The technical root cause of this vulnerability stems from inadequate input validation within the SIP processing module of Cisco IOS. When a malicious actor sends a crafted SIP REGISTER message containing malformed parameters or unexpected data structures, the IOS software fails to properly handle the memory allocation and deallocation processes. This results in memory segments being allocated but never released back to the system, creating a gradual accumulation of memory usage that can ultimately lead to system instability and complete denial of service. The vulnerability is particularly concerning because SIP REGISTER messages are commonly used in enterprise VoIP deployments, making the attack surface quite broad and potentially impactful for organizations relying on Cisco networking equipment.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the availability of critical communication infrastructure within enterprise networks. When exploited successfully, the memory leak can cause the affected Cisco device to consume increasing amounts of memory until the system becomes unresponsive or crashes entirely. This creates a denial of service condition that affects not only the targeted device but can also disrupt VoIP services throughout the network, potentially impacting business communications, emergency services, and critical infrastructure that depends on reliable voice communication systems. Network administrators may experience difficulty in maintaining service availability and could face significant downtime during exploitation attempts.
Organizations should implement immediate mitigations including applying the relevant Cisco IOS software updates to versions 15.0(1)XA5 or later, which contain patches addressing the memory leak in the SIP processing module. Network segmentation strategies should be employed to isolate VoIP traffic and limit the potential impact of exploitation attempts. Additionally, implementing rate limiting and access control lists on UDP port 5060, which is the standard port for SIP communication, can help reduce the attack surface. Monitoring network traffic for unusual patterns in SIP REGISTER message processing and implementing intrusion detection systems can provide early warning of potential exploitation attempts. The vulnerability aligns with CWE-401, which describes improper handling of memory allocation and deallocation, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing network-wide monitoring solutions that can detect abnormal memory consumption patterns and automatically alert security teams to potential exploitation attempts.