CVE-2013-1203 in ASA CX
Summary
by MITRE
Cisco ASA CX Context-Aware Security Software allows remote attackers to cause a denial of service (device reload) via crafted TCP packets that appear to have been forwarded by a Cisco Adaptive Security Appliances (ASA) device, aka Bug ID CSCue88386.
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Analysis
by VulDB Data Team • 05/11/2017
The vulnerability identified as CVE-2013-1203 affects Cisco ASA CX Context-Aware Security Software, a critical component in network security infrastructure designed to provide advanced threat detection and protection. This flaw represents a significant denial of service weakness that can be exploited by remote attackers to disrupt network operations. The vulnerability specifically manifests when the software processes crafted TCP packets that are designed to mimic traffic forwarded by Cisco Adaptive Security Appliances devices, creating a scenario where legitimate network operations become compromised. The bug ID CSCue88386 serves as the internal tracking reference for this particular security issue within Cisco's vulnerability management system.
The technical exploitation of this vulnerability occurs through the manipulation of TCP packet structures that appear to originate from legitimate ASA devices. When the ASA CX software encounters these specially crafted packets, it fails to properly handle the packet forwarding logic, leading to an unexpected system state that ultimately results in device reload or complete system reboot. This behavior stems from inadequate input validation and error handling mechanisms within the packet processing modules of the context-aware security software. The flaw essentially allows attackers to trigger a cascading failure condition that forces the device to restart its operational processes, effectively rendering the security appliance unavailable to protect the network infrastructure.
The operational impact of this vulnerability extends beyond simple service disruption, as it fundamentally compromises the availability of critical network security services. Organizations relying on Cisco ASA CX appliances for context-aware security monitoring face potential exposure to extended downtime periods that can last from several minutes to hours depending on the recovery mechanisms in place. The attack vector's remote nature means that adversaries can exploit this weakness from outside the network perimeter, making it particularly dangerous for organizations that deploy these appliances in perimeter security configurations. Network administrators may experience cascading effects where the device reload causes temporary loss of security monitoring capabilities, potentially creating windows of vulnerability during the recovery process.
Mitigation strategies for CVE-2013-1203 should prioritize immediate implementation of Cisco's recommended security patches and firmware updates to address the underlying packet handling flaws. Network segmentation and access control measures can help limit the attack surface by restricting unauthorized access to the vulnerable ASA CX appliances. Implementing network monitoring solutions that can detect anomalous TCP packet patterns may provide early warning capabilities before full exploitation occurs. Organizations should also consider deploying redundant security appliances to maintain network protection during potential maintenance windows or emergency reload scenarios. From a compliance perspective, this vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and maps to ATT&CK technique T1499.004 for network denial of service attacks, emphasizing the need for robust input validation and network resilience measures.
This vulnerability demonstrates the critical importance of proper input validation in security appliances and highlights how seemingly minor flaws in packet processing logic can lead to complete system compromise. The exploitation mechanism underscores the need for comprehensive security testing of network infrastructure components, particularly those handling complex packet forwarding operations. Organizations should maintain updated threat intelligence feeds to monitor for similar vulnerabilities in their security infrastructure and implement continuous monitoring protocols to detect potential exploitation attempts. The incident also reinforces the necessity of maintaining detailed incident response procedures that account for security appliance failures and their potential cascading effects on overall network security posture.