CVE-2019-12698 in ASA
Summary
by MITRE
A vulnerability in the WebVPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause increased CPU utilization on an affected device. The vulnerability is due to excessive processing load for a specific WebVPN HTTP page request. An attacker could exploit this vulnerability by sending multiple WebVPN HTTP page load requests for a specific URL. A successful exploit could allow the attacker to increase CPU load on the device, resulting in a denial of service (DoS) condition, which could cause traffic to be delayed through the device.
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Analysis
by VulDB Data Team • 12/29/2023
The vulnerability identified as CVE-2019-12698 represents a significant denial of service weakness within Cisco's Adaptive Security Appliance and Firepower Threat Defense software platforms. This flaw specifically targets the WebVPN functionality, which serves as a critical component for remote access and secure network connectivity. The vulnerability stems from an inefficient processing mechanism that fails to properly handle certain HTTP requests, creating a scenario where legitimate network traffic can be disrupted through malicious exploitation. Security professionals must understand that this issue affects organizations relying on Cisco's security infrastructure for remote access capabilities, making it particularly concerning for enterprises with distributed workforces and remote access requirements.
The technical implementation of this vulnerability involves a specific WebVPN HTTP page request that triggers excessive CPU utilization on affected devices. When an attacker sends multiple requests targeting a particular URL within the WebVPN interface, the system's processing mechanisms become overwhelmed with repetitive or resource-intensive operations. This condition creates a resource exhaustion scenario where the device's central processing unit becomes saturated with requests that should be handled efficiently. The flaw demonstrates poor input validation and resource management within the WebVPN module, allowing malicious actors to leverage normal operational procedures for disruptive purposes. This behavior aligns with CWE-400, which addresses improper resource management and excessive resource consumption in software applications.
The operational impact of CVE-2019-12698 extends beyond simple service disruption to potentially compromise business continuity and network availability. Organizations utilizing affected Cisco appliances may experience significant delays in network traffic processing, as the device becomes overwhelmed with processing demands from the malicious requests. The DoS condition can affect legitimate users attempting to establish remote connections through the WebVPN service, creating productivity losses and potential security gaps. Network administrators may find their devices unable to handle normal traffic loads while under attack, leading to cascading effects throughout the organization's network infrastructure. This vulnerability particularly affects organizations with critical remote access requirements, where service availability directly impacts operational efficiency and security posture.
Mitigation strategies for CVE-2019-12698 should focus on both immediate defensive measures and long-term architectural improvements. Cisco has released patches and updates addressing this vulnerability, which organizations must implement promptly to eliminate the risk of exploitation. Network administrators should consider implementing access controls and rate limiting for WebVPN HTTP requests to prevent the specific attack pattern from overwhelming system resources. The implementation of intrusion detection systems can help identify and block suspicious traffic patterns associated with this vulnerability, providing an additional layer of defense. Security teams should also consider network segmentation strategies to isolate WebVPN services and limit the potential impact of successful exploitation attempts. This vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against resource exhaustion attacks that leverage legitimate application features for malicious purposes.