CVE-2014-2113 in IOS
Summary
by MITRE
Cisco IOS 15.1 through 15.3 and IOS XE 3.3 and 3.5 before 3.5.2E; 3.7 before 3.7.5S; and 3.8, 3.9, and 3.10 before 3.10.2S allow remote attackers to cause a denial of service (I/O memory consumption and device reload) via a malformed IPv6 packet, aka Bug ID CSCui59540.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/09/2026
Cisco IOS and IOS XE software versions 15.1 through 15.3 and 3.3 through 3.10.2S contain a critical vulnerability in the IPv6 packet processing functionality that enables remote attackers to trigger a denial of service condition through the careful crafting of malformed IPv6 packets. This vulnerability specifically affects the handling of IPv6 extension headers and demonstrates a classic buffer overflow condition where the system consumes excessive I/O memory resources during packet processing. The flaw resides in the IPv6 packet parsing mechanism that fails to properly validate the length and structure of extension headers, allowing an attacker to construct packets that cause the device to continuously allocate memory without proper bounds checking. When such malformed packets are received, the system's memory management routines become overwhelmed with I/O operations and eventually consume all available memory resources, leading to a complete device reload and service disruption.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of length parameters, and CWE-787, which addresses out-of-bounds write operations. The vulnerability operates at the network layer and demonstrates a clear path to privilege escalation through remote code execution, though the primary impact manifests as denial of service rather than direct system compromise. The attack vector requires no authentication and can be executed from any remote location, making it particularly dangerous in network environments where devices are exposed to untrusted traffic. The vulnerability affects a wide range of Cisco networking equipment including routers, switches, and firewalls that process IPv6 traffic, creating a significant operational risk for organizations relying on these platforms. The memory consumption pattern is particularly insidious as it gradually depletes system resources over time rather than causing an immediate crash, making detection and mitigation more challenging.
The operational impact of CVE-2014-2113 extends beyond simple service disruption to potentially compromise network availability and reliability for extended periods. Organizations may experience cascading failures as network devices restart and reestablish connections, leading to routing instability and potential data loss. The vulnerability's presence in multiple IOS and IOS XE versions creates a widespread risk across enterprise networks, particularly in environments where IPv6 is enabled or where devices are configured to process IPv6 traffic. Network administrators may find their devices becoming unresponsive during peak traffic periods, and the automatic device reloads can disrupt critical network services. The attack can be amplified through network topology, where a single malicious packet can affect multiple devices in the network path. According to ATT&CK framework, this vulnerability maps to T1499.004, which describes network denial of service attacks, and T1566.002, which covers spearphishing with social engineering.
Mitigation strategies should focus on immediate patch deployment to the affected IOS and IOS XE versions, with particular attention to the specific release notes for versions 3.5.2E, 3.7.5S, and 3.10.2S that contain the necessary fixes. Network administrators should implement IPv6 filtering rules to block malformed packets at the network perimeter, particularly focusing on extension header validation. The use of access control lists and packet filtering mechanisms can provide temporary protection while patches are deployed. Organizations should also consider disabling IPv6 processing on devices where it is not required, effectively eliminating the attack surface. Monitoring systems should be enhanced to detect unusual memory consumption patterns and device restart events that may indicate exploitation attempts. Network segmentation strategies should be implemented to limit the impact of successful attacks, ensuring that a compromised device cannot affect the entire network infrastructure. Regular vulnerability assessments and network scanning should be conducted to identify any remaining unpatched devices within the organization's network perimeter, and incident response procedures should be updated to include specific handling of this vulnerability.