CVE-2019-1708 in ASA
Summary
by MITRE
A vulnerability in the Internet Key Exchange Version 2 Mobility and Multihoming Protocol (MOBIKE) feature for the Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to the incorrect processing of certain MOBIKE packets. An attacker could exploit this vulnerability by sending crafted MOBIKE packets to an affected device to be processed. A successful exploit could cause an affected device to continuously consume memory and eventually reload, resulting in a DoS condition. The MOBIKE feature is supported only for IPv4 addresses.
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Analysis
by VulDB Data Team • 09/12/2023
The vulnerability identified as CVE-2019-1708 resides within the Internet Key Exchange Version 2 Mobility and Multihoming Protocol implementation on Cisco Adaptive Security Appliance and Cisco Firepower Threat Defense devices. This flaw specifically affects the processing of MOBIKE packets which are essential for maintaining secure connections when network topology changes occur. The issue manifests as a memory management error that occurs when the affected devices receive specially crafted MOBIKE packets designed to trigger improper resource handling. This vulnerability represents a critical weakness in the IKEv2 protocol implementation that could be exploited by remote attackers without authentication requirements. The affected systems process these malicious packets through their security infrastructure, leading to abnormal resource consumption patterns that ultimately result in system instability and potential service disruption.
The technical root cause of this vulnerability stems from improper validation and handling of MOBIKE packet structures within the Cisco ASA and FTD software implementations. When these devices receive malformed or specially constructed MOBIKE packets, the processing logic fails to properly manage memory allocation and deallocation cycles, leading to gradual memory consumption that eventually forces the system to reload. This memory leak behavior creates a cascading effect where the device continuously consumes available memory resources until system stability is compromised. The vulnerability specifically targets the IPv4 implementation of the MOBIKE feature, as indicated by the description, making it distinct from potential IPv6 variants that might exist in other implementations. This flaw aligns with CWE-400, which classifies memory leak vulnerabilities as a common weakness in software design that can lead to resource exhaustion and system instability.
The operational impact of CVE-2019-1708 extends beyond simple service interruption to potentially compromise network security infrastructure availability. Organizations relying on Cisco ASA and FTD devices for their security operations face significant risk as attackers could exploit this vulnerability to create sustained denial of service conditions that disrupt legitimate network traffic. The remote nature of the attack means that threat actors do not require physical access or network credentials to execute the exploit, making it particularly dangerous for perimeter security devices that are designed to be accessible from external networks. The automatic reload behavior of affected systems creates an additional operational challenge as it can lead to unexpected service interruptions and potential loss of security monitoring capabilities during the restart process. This vulnerability directly impacts the availability aspect of the CIA triad and represents a significant concern for organizations that depend on continuous network security operations.
Mitigation strategies for CVE-2019-1708 should prioritize immediate implementation of Cisco's security advisories and software patches that address the specific MOBIKE packet processing logic. Organizations should also consider implementing network segmentation controls that limit exposure of affected devices to untrusted networks while monitoring for unusual packet patterns that may indicate exploitation attempts. The implementation of access control lists and firewall rules that restrict MOBIKE traffic to only trusted sources can serve as temporary protective measures until permanent patches are deployed. Network administrators should also configure logging and monitoring systems to detect abnormal memory usage patterns that may indicate exploitation attempts. From a defensive perspective, this vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing proper network hygiene practices. The ATT&CK framework categorizes this type of vulnerability under the 'Defense Evasion' and 'Impact' tactics, where attackers leverage system weaknesses to achieve persistent availability disruption. Organizations should also consider implementing redundant security infrastructure to ensure continued protection even during potential exploitation events, as the vulnerability specifically targets core security appliance functionality that is critical to network defense operations.