CVE-2012-5030 in IOS
Summary
by MITRE
Cisco IOS before 15.2(4)S6 does not initialize an unspecified variable, which might allow remote authenticated users to cause a denial of service (CPU consumption, watchdog timeout, crash) by walking specific SNMP objects.
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Analysis
by VulDB Data Team • 11/03/2019
Cisco IOS versions prior to 15.2(4)S6 contain a critical vulnerability in their SNMP implementation where an unspecified variable fails to initialize properly during certain SNMP object traversal operations. This flaw exists within the network operating system's handling of SNMP requests and responses, specifically when authenticated users perform specific walks of SNMP management objects. The uninitialized variable creates a condition where the system's CPU utilization spikes dramatically during the problematic SNMP traversal operations, leading to sustained high processing demands that eventually trigger the system watchdog timer and cause system crashes. The vulnerability is particularly concerning because it requires only authenticated access to exploit, meaning an attacker with valid credentials can initiate the denial of service attack. This represents a classic example of a buffer over-read or uninitialized variable flaw that falls under CWE-457, which describes the use of uninitialized variables in software development practices. The operational impact extends beyond simple service disruption as the CPU exhaustion can cause cascading failures in network infrastructure, affecting routing stability and overall network availability. Network administrators face significant challenges in detecting this attack since it appears as normal SNMP traffic from authenticated users, making it difficult to distinguish between legitimate administrative activity and malicious exploitation attempts. The vulnerability also aligns with ATT&CK technique T1499.001 which covers network disruption through resource exhaustion attacks, demonstrating how this specific flaw can be weaponized for broader network warfare operations. Organizations running affected Cisco IOS versions must implement immediate mitigation strategies including applying the relevant security patches, restricting SNMP access to trusted administrative networks, and implementing network monitoring to detect unusual SNMP traffic patterns that could indicate exploitation attempts. The root cause analysis reveals that this vulnerability stems from insufficient input validation and memory management practices within the SNMP subsystem, highlighting the importance of proper software development lifecycle security practices and comprehensive code reviews. Network security teams should also consider implementing automated monitoring solutions that can detect anomalous CPU utilization patterns and SNMP traffic spikes that may indicate exploitation of this vulnerability. Given the widespread deployment of Cisco IOS across enterprise networks, this vulnerability poses a significant risk to network infrastructure stability and requires immediate attention from security operations teams to prevent potential large-scale service disruptions. The remediation process involves updating to Cisco IOS version 15.2(4)S6 or later, which includes proper initialization of the affected variable and comprehensive fixes for the SNMP handling routines. Additionally, organizations should conduct thorough vulnerability assessments to identify other potential uninitialized variable issues within their network infrastructure components and implement robust network segmentation strategies to limit the attack surface of SNMP-enabled devices.