CVE-2014-3386 in ASA
Summary
by MITRE
The GPRS Tunneling Protocol (GTP) inspection engine in Cisco ASA Software 8.2 before 8.2(5.51), 8.4 before 8.4(7.15), 8.7 before 8.7(1.13), 9.0 before 9.0(4.8), and 9.1 before 9.1(5.1) allows remote attackers to cause a denial of service (device reload) via a crafted series of GTP packets, aka Bug ID CSCum56399.
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Analysis
by VulDB Data Team • 02/21/2022
The vulnerability identified as CVE-2014-3386 represents a critical denial of service flaw within Cisco Adaptive Security Appliance (ASA) software that affects multiple versions of the GPRS Tunneling Protocol (GTP) inspection engine. This weakness specifically targets the handling of crafted GTP packets that can trigger unexpected behavior in the network security device, ultimately leading to complete device reload and service disruption. The vulnerability impacts Cisco ASA Software versions 8.2 prior to 8.2(5.51), 8.4 prior to 8.4(7.15), 8.7 prior to 8.7(1.13), 9.0 prior to 9.0(4.8), and 9.1 prior to 9.1(5.1), making it a widespread issue affecting a significant portion of Cisco's security appliance deployments. The flaw manifests when the GTP inspection engine processes malformed or specially crafted GTP packet sequences that cause memory corruption or state management errors within the ASA's processing pipeline.
This vulnerability operates at the network protocol inspection layer where the ASA software analyzes and validates GTP traffic passing through the security device. GTP is commonly used in mobile network environments for tunneling user data between mobile network elements, and the ASA's GTP inspection functionality is designed to monitor and control this traffic flow. However, the inspection engine contains a flaw in its packet parsing logic that fails to properly validate certain GTP packet structures, particularly those involving specific sequence numbers, message types, or tunnel identifiers. When an attacker sends a carefully constructed series of GTP packets that exploit this parsing weakness, the ASA software becomes unable to process the traffic correctly, leading to a system crash that necessitates a complete device reload to restore normal operation.
The operational impact of this vulnerability extends beyond simple service disruption to represent a serious threat to network availability and reliability. Organizations relying on Cisco ASA appliances for network security may experience complete loss of connectivity for the protected network segments when attackers exploit this flaw, as the device reload process effectively removes the security appliance from service until manual intervention occurs. The attack requires minimal resources from the attacker, who only needs to send a specific sequence of packets to trigger the vulnerability, making it particularly dangerous for environments where network availability is critical. Network administrators may face significant challenges in detecting such attacks, as the malicious traffic appears to be legitimate GTP traffic, and the device failure occurs without proper logging of the specific triggering conditions.
The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation in network protocol processing. From an adversarial perspective, this flaw maps to ATT&CK technique T1499.004, which covers network denial of service attacks through exploitation of system vulnerabilities. Organizations should prioritize immediate patching of affected ASA appliances, as Cisco has released software updates addressing this vulnerability in the subsequent versions of their ASA software. The mitigation strategy requires careful planning to minimize service disruption during patch deployment, including staging updates in non-production environments first. Network monitoring should be enhanced to detect unusual GTP traffic patterns that might indicate exploitation attempts, and administrators should implement proper access controls to limit exposure of the affected appliances to untrusted networks.
The broader implications of this vulnerability highlight the importance of thorough protocol validation in security appliances, particularly those handling complex network protocols like GTP that are critical to mobile network operations. This flaw demonstrates how seemingly minor parsing issues in protocol inspection engines can result in complete system failures, emphasizing the need for comprehensive testing of security device functionality. Organizations should also consider implementing redundant security appliances or alternative network segmentation strategies to reduce the impact of similar vulnerabilities, as the complete device reload required by this flaw can take several minutes to complete, potentially leaving networks unprotected during the recovery process.