CVE-2012-1310 in IOS
Summary
by MITRE
Memory leak 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 crafted IP packets, aka Bug ID CSCto89536.
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability identified as CVE-2012-1310 represents a critical memory leak flaw within Cisco IOS operating systems affecting versions 12.4, 15.0, 15.1, and 15.2. This issue specifically impacts the Zone-Based Firewall implementation which serves as a core security feature for network segmentation and traffic control in enterprise environments. The vulnerability manifests when the system processes crafted IP packets that exploit improper memory management within the firewall processing pipeline, ultimately leading to progressive memory consumption that can exhaust available system resources.
The technical flaw stems from inadequate memory deallocation mechanisms within the Zone-Based Firewall module when handling malformed or specially crafted IP packets. When these packets traverse the firewall, the system fails to properly release allocated memory resources, causing a gradual accumulation of memory usage over time. This memory leak directly correlates to the Common Weakness Enumeration classification under CWE-401: "Improper Release of Memory" which specifically addresses weaknesses where software fails to properly release allocated memory resources. The vulnerability operates at the network protocol level where the firewall engine processes incoming packets and maintains state information for traffic filtering decisions, making it particularly dangerous as it can be triggered through normal network traffic without requiring authentication or elevated privileges.
The operational impact of this vulnerability extends beyond simple resource exhaustion to potentially cause complete device unavailability through memory consumption or forced device reloads. Attackers can exploit this weakness by sending a sequence of crafted IP packets to a vulnerable Cisco IOS device, causing progressive memory depletion that eventually forces the system to either crash or require manual intervention for recovery. This denial of service condition severely impacts network availability and can disrupt critical business operations, particularly in environments where network infrastructure devices serve as primary connectivity points for enterprise networks or internet gateways. The vulnerability affects devices configured with Zone-Based Firewall policies, making it particularly concerning for organizations that rely on this security feature for network segmentation and access control enforcement.
Organizations affected by this vulnerability should prioritize immediate mitigation through Cisco's recommended security patches and updates, specifically targeting the software versions mentioned in the advisory. The ATT&CK framework classification for this vulnerability would fall under T1499.004: "Endpoint Denial of Service" with potential implications for T1566.001: "Phishing" if attackers leverage the service disruption for social engineering purposes. Mitigation strategies should include implementing network segmentation to isolate vulnerable devices, monitoring for unusual memory consumption patterns, and deploying intrusion detection systems to identify potential exploitation attempts. Additionally, administrators should consider temporarily disabling Zone-Based Firewall functionality on affected devices while patches are applied, and implementing regular memory monitoring procedures to detect early signs of memory leak exploitation. The vulnerability underscores the critical importance of maintaining up-to-date security patches for network infrastructure devices and demonstrates how seemingly minor memory management flaws can result in significant operational disruptions.