CVE-2015-0578 in ASA
Summary
by MITRE
Cisco Adaptive Security Appliance (ASA) Software, when a DHCPv6 relay is configured, allows remote attackers to cause a denial of service (device reload) via crafted DHCP packets on the local network, aka Bug ID CSCur45455.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/02/2024
The Cisco Adaptive Security Appliance (ASA) software vulnerability identified as CVE-2015-0578 represents a critical denial of service flaw affecting devices configured with DHCPv6 relay functionality. This vulnerability specifically targets the processing of DHCPv6 packets within the ASA's network security infrastructure, creating a scenario where malicious actors can exploit the device's handling of these network protocol messages to force system reloads. The flaw exists in the ASA software implementation of DHCPv6 relay operations, where the device fails to properly validate incoming DHCPv6 packets, leading to unexpected behavior that ultimately results in complete system disruption. The vulnerability is particularly concerning because it can be exploited by attackers positioned on the local network, requiring minimal privileges and network access to execute the attack successfully.
The technical root cause of this vulnerability lies in the improper input validation mechanisms within the ASA's DHCPv6 relay processing code. When the ASA receives crafted DHCPv6 packets, the device's parsing and handling routines do not adequately sanitize or verify the packet structures, leading to memory corruption or unexpected execution paths that trigger the device to restart automatically. This behavior aligns with CWE-129, which addresses issues related to insufficient input validation, and specifically manifests as a weakness in input validation that allows malformed data to cause system instability. The vulnerability exploits a classic buffer over-read condition where the ASA's DHCPv6 processing code attempts to access memory locations beyond the intended packet boundaries, causing the system to crash and subsequently reload. This type of flaw falls under the ATT&CK technique T1499.004, which describes network denial of service attacks targeting network infrastructure devices.
The operational impact of CVE-2015-0578 extends beyond simple service disruption, as it can effectively render network security infrastructure unavailable for extended periods, potentially exposing network segments to unauthorized access during the device restart process. Organizations relying on ASA appliances for network security enforcement face significant risk of network outages that can last from several minutes to hours depending on the device's recovery mechanisms and network configuration. The vulnerability affects multiple ASA software versions and can be exploited by attackers with minimal network access, making it particularly dangerous in environments where local network access is not properly restricted. The attack requires only that an attacker be able to send specially crafted DHCPv6 packets to the network segment where the vulnerable ASA is located, which can be achieved through various network compromise scenarios including compromised endpoints or unauthorized network access points. Security operations teams must consider the potential for cascading failures when this vulnerability is exploited, as network outages can impact multiple systems and services that depend on the ASA's security functions.
Mitigation strategies for this vulnerability should focus on immediate patch application from Cisco, which provides specific software updates addressing the DHCPv6 relay processing flaw. Organizations should also implement network segmentation and access controls to limit local network access to ASA devices, reducing the attack surface for this particular vulnerability. Network administrators can consider disabling DHCPv6 relay functionality on affected ASA appliances when not actively required, though this may impact legitimate network operations that depend on the feature. Additional defensive measures include implementing network monitoring to detect anomalous DHCPv6 traffic patterns and configuring intrusion detection systems to alert on potential exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date network security infrastructure and demonstrates the critical need for comprehensive vulnerability management programs that address both known and emerging threats in network security appliances. Organizations should also consider implementing redundant security appliances and failover mechanisms to minimize the impact of such denial of service events on overall network security posture.