CVE-2014-2182 in ASA
Summary
by MITRE
Cisco Adaptive Security Appliance (ASA) Software, when DHCPv6 replay is configured, allows remote attackers to cause a denial of service (device reload) via a crafted DHCPv6 packet, aka Bug ID CSCun45520.
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Analysis
by VulDB Data Team • 05/12/2026
The vulnerability identified as CVE-2014-2182 affects Cisco Adaptive Security Appliance (ASA) software versions that have DHCPv6 replay functionality enabled. This flaw represents a critical denial of service condition that can be exploited by remote attackers to force a complete device reload, effectively disrupting network security services. The vulnerability specifically manifests when the ASA device is configured to perform DHCPv6 replay operations, which are typically used to maintain network connectivity by replaying DHCPv6 messages to ensure proper address assignment and network access for clients.
The technical implementation of this vulnerability stems from insufficient input validation within the ASA's DHCPv6 processing mechanism. When a specially crafted DHCPv6 packet is received by an affected ASA device, the system fails to properly handle the malformed packet structure, leading to a buffer overflow or memory corruption condition. This memory management failure causes the ASA software to crash and subsequently restart, resulting in the complete device reload. The flaw exists in the packet parsing and validation logic that processes DHCPv6 replay operations, where the system does not adequately sanitize or validate the incoming DHCPv6 message parameters before processing them.
From an operational perspective, this vulnerability presents a significant risk to network infrastructure security as it allows remote attackers to perform denial of service attacks without requiring authentication or privileged access. The impact extends beyond simple service disruption since the ASA device serves as a critical network security component, providing firewall protection, intrusion prevention, and secure remote access capabilities. When the device reloads, all active security policies are lost, network traffic is temporarily blocked, and security monitoring capabilities are suspended. This creates a window of vulnerability where the network becomes exposed to potential attacks during the device recovery period. The attack can be executed from any location on the network where the attacker can send DHCPv6 packets, making it particularly dangerous in environments where DHCPv6 traffic flows freely between network segments.
The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation in network security appliances. From the MITRE ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for network disruption attacks and represents a critical weakness in the device's network protocol handling capabilities. Organizations running affected ASA software versions face immediate operational risks, as the vulnerability can be exploited by malicious actors to create service outages that may go undetected for extended periods. The attack vector is particularly concerning because it requires minimal privileges and can be executed remotely, making it an attractive target for both opportunistic attackers and organized threat groups seeking to disrupt network operations.
Cisco has released patches and software updates to address this vulnerability through their security advisory process, and organizations should immediately implement the recommended software updates to mitigate the risk. Network administrators should also consider implementing additional monitoring and intrusion detection measures to identify potential exploitation attempts, as the device reload will typically generate system logs and network traffic anomalies that can be detected by security monitoring systems. The vulnerability demonstrates the importance of proper input validation and memory management in network security appliances, as these devices often become primary targets for attackers seeking to disrupt network operations and compromise security infrastructure.