CVE-2015-4241 in ASA
Summary
by MITRE
Cisco Adaptive Security Appliance (ASA) Software 9.3(2) allows remote attackers to cause a denial of service (system reload) by sending crafted OSPFv2 packets on the local network, aka Bug ID CSCut52679.
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Analysis
by VulDB Data Team • 05/23/2022
The Cisco Adaptive Security Appliance ASA Software version 9.3(2) contains a critical vulnerability that enables remote attackers to induce a denial of service condition through manipulation of OSPFv2 routing protocol packets. This vulnerability specifically affects devices operating within the local network environment and represents a significant security flaw that can compromise network availability and operational continuity. The flaw manifests when the system processes crafted OSPFv2 packets, leading to an unexpected system reload that disrupts network services and potentially creates unauthorized access opportunities for malicious actors.
The technical implementation of this vulnerability resides in the ASA software's handling of OSPFv2 packet processing within the routing protocol stack. When the appliance receives malformed or specially crafted OSPFv2 packets, the processing logic fails to properly validate input parameters, resulting in a memory corruption or buffer overflow condition. This flaw falls under the category of improper input validation as defined by CWE-20, where the system does not adequately sanitize or validate the data it receives from network sources. The vulnerability specifically impacts the OSPFv2 implementation within the ASA's routing engine, where the software fails to properly handle edge cases in packet parsing, leading to system instability and subsequent reload operations.
The operational impact of this vulnerability extends beyond simple service disruption to potentially create broader network security implications. Network administrators may experience unexpected downtime as the affected ASA appliances automatically reload, interrupting network connectivity and potentially exposing the network to additional threats during the recovery period. The vulnerability's remote nature means attackers do not require physical access or network credentials to exploit the flaw, making it particularly dangerous in environments where network segmentation is not properly implemented. During the system reload, network traffic is temporarily disrupted, potentially affecting critical business applications and services that depend on stable network connectivity, while also creating opportunities for attackers to observe network behavior or perform additional reconnaissance activities.
Mitigation strategies for this vulnerability should include immediate deployment of Cisco's official security patches and updates that address the specific OSPFv2 processing flaw. Network administrators should implement network segmentation and access control measures to limit the scope of potential exploitation, ensuring that OSPFv2 traffic is properly filtered and restricted to trusted network segments. The implementation of intrusion detection systems and network monitoring tools can help detect anomalous OSPFv2 packet patterns that may indicate exploitation attempts. Additionally, organizations should consider disabling OSPFv2 routing protocols on ASA appliances where they are not strictly required, reducing the attack surface and limiting potential exploitation vectors. This vulnerability aligns with ATT&CK technique T1499.004 for network denial of service, where adversaries leverage protocol implementation flaws to disrupt network services and maintain persistent access to compromised systems through the resulting service interruptions and recovery processes.