CVE-2014-3359 in IOS
Summary
by MITRE
Memory leak in Cisco IOS 15.1 through 15.4 and IOS XE 3.4.xS, 3.5.xS, 3.6.xS, and 3.7.xS before 3.7.6S; 3.8.xS, 3.9.xS, and 3.10.xS before 3.10.1S; and 3.11.xS before 3.12S allows remote attackers to cause a denial of service (memory consumption or device reload) via malformed DHCPv6 packets, aka Bug ID CSCum90081.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/17/2024
The vulnerability described in CVE-2014-3359 represents a critical memory leak flaw affecting Cisco IOS and IOS XE operating systems across multiple version ranges. This issue specifically targets the handling of DHCPv6 packets, which are essential for IPv6 network configuration and management. The vulnerability exists in Cisco IOS versions 15.1 through 15.4 and IOS XE versions 3.4.xS through 3.12.xS, with specific patches required for different release branches. The flaw allows remote attackers to exploit the system through carefully crafted malformed DHCPv6 packets that trigger memory allocation issues within the network device's processing mechanisms. This vulnerability falls under the CWE-401 weakness category, specifically addressing memory leak conditions where allocated memory is not properly released back to the system. The impact of this vulnerability is severe as it can lead to progressive memory consumption that eventually results in device instability, requiring manual intervention to restore normal operations through device reloads.
The technical exploitation of this vulnerability occurs when network devices receive malformed DHCPv6 packets that contain unexpected or invalid data structures within the DHCPv6 message format. These malformed packets trigger improper memory handling within the IOS or IOS XE processing stack, causing the system to allocate memory resources without subsequently releasing them. The memory leak accumulates over time as attackers repeatedly send these malformed packets, gradually consuming available memory resources on the device. This process can be initiated remotely without requiring authentication, making it particularly dangerous for network infrastructure devices that are often accessible from untrusted networks. The vulnerability affects the core network processing functionality, specifically targeting the DHCPv6 implementation within the operating system's network stack, which is responsible for managing IPv6 address assignment and network configuration parameters. According to ATT&CK framework, this vulnerability maps to T1071.004 (Application Layer Protocol: DNS) and T1499.004 (Endpoint Denial of Service) techniques, as it exploits application layer protocols to cause service disruption through memory exhaustion.
The operational impact of CVE-2014-3359 extends beyond simple denial of service conditions, as it can cause complete device instability and require extensive downtime for recovery operations. Network administrators may observe gradual performance degradation before complete system failure, making early detection challenging. The vulnerability affects critical network infrastructure components including routers, switches, and unified border routers that rely on DHCPv6 for IPv6 network management. When exploited successfully, the memory leak can cause devices to become unresponsive, requiring manual restart procedures that may interrupt network services for extended periods. The attack vector is particularly concerning because it requires minimal privileges and can be executed from remote locations, making it suitable for both accidental and malicious exploitation scenarios. Organizations with extensive deployments of affected Cisco devices may experience cascading failures if multiple devices are compromised simultaneously, potentially leading to widespread network outages and service disruptions across critical infrastructure. The vulnerability's persistence means that even after initial exploitation, the memory consumption continues until the device is manually reset or the system is rebooted.
Mitigation strategies for this vulnerability require immediate implementation of software updates and patches provided by Cisco, specifically targeting the affected IOS and IOS XE versions. Organizations should prioritize patching devices running vulnerable software versions, with particular attention to those in high-availability environments where network uptime is critical. Network segmentation and access control measures can help limit exposure by restricting which networks can receive DHCPv6 traffic from untrusted sources. Implementing rate limiting on DHCPv6 packet processing and monitoring for unusual memory consumption patterns can aid in early detection of exploitation attempts. Cisco recommends applying the relevant security patches that address the memory leak in the DHCPv6 processing code, with specific versions identified for each affected release branch. Network administrators should also consider implementing intrusion detection systems that can identify malformed DHCPv6 packets and alert on suspicious traffic patterns. Regular monitoring of device memory usage and system logs should be established to detect potential exploitation attempts. The vulnerability highlights the importance of maintaining current security patches and conducting regular vulnerability assessments to identify and remediate similar memory management issues in network infrastructure devices. Additionally, implementing proper network access controls and limiting unnecessary DHCPv6 service exposure can significantly reduce the attack surface for this particular vulnerability.