CVE-2016-1312 in ASA 5500
Summary
by MITRE
The HTTPS inspection engine in the Content Security and Control Security Services Module (CSC-SSM) 6.6 before 6.6.1164.0 for Cisco ASA 5500 devices allows remote attackers to cause a denial of service (memory consumption or device reload) via a flood of HTTPS packets, aka Bug ID CSCue76147.
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Analysis
by VulDB Data Team • 07/10/2022
The vulnerability described in CVE-2016-1312 represents a critical denial of service weakness within Cisco's Adaptive Security Appliance (ASA) 5500 series devices, specifically affecting the Content Security and Control Security Services Module (CSC-SSM) version 6.6 prior to 6.6.1164.0. This flaw resides in the HTTPS inspection engine component that is responsible for analyzing and filtering secure web traffic passing through the firewall. The vulnerability enables remote attackers to exploit a memory management issue that can lead to either excessive memory consumption or complete device reloading, effectively rendering the security appliance non-functional and disrupting network operations.
The technical nature of this vulnerability stems from improper handling of HTTPS packet streams within the CSC-SSM module's inspection engine. When subjected to a flood of carefully crafted HTTPS packets, the system fails to properly manage memory allocation and deallocation processes, causing memory exhaustion that ultimately forces the device to reload its operating system. This behavior aligns with CWE-400, which categorizes "Uncontrolled Resource Consumption" as a common weakness that can lead to denial of service conditions. The attack vector requires no authentication and can be executed remotely, making it particularly dangerous as it can be exploited by any attacker with network access to the affected device.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the entire security infrastructure of an organization that relies on Cisco ASA appliances for network protection. When an ASA device experiences a reload due to memory exhaustion, all network traffic passing through that device becomes vulnerable to attacks during the downtime period. Network administrators face the challenge of maintaining service availability while applying patches, as the device may become temporarily unusable during the reload process. This vulnerability particularly affects enterprise networks where the ASA serves as a critical security gateway, potentially exposing sensitive data and systems to unauthorized access during the disruption period.
Organizations should implement immediate mitigations including applying the relevant Cisco security patches that address the memory management issues in the CSC-SSM module. Network segmentation and traffic monitoring should be enhanced to detect unusual packet flooding patterns that may indicate exploitation attempts. The ATT&CK framework categorizes this type of attack under T1499.004, which covers "Endpoint Denial of Service," and organizations should consider implementing network-level controls to limit the impact of such attacks. Additionally, implementing rate limiting and connection tracking mechanisms within the ASA configuration can help reduce the effectiveness of packet flooding attacks. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in other network security components, ensuring comprehensive protection against resource exhaustion attacks that could compromise the overall security posture of the network infrastructure.