CVE-2009-4917 in ASA 5580
Summary
by MITRE
Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5580 series devices with software before 8.1(2) allows remote attackers to cause a denial of service (device reload) via a high volume of SIP traffic, aka Bug ID CSCsr65901.
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Analysis
by VulDB Data Team • 04/20/2017
The vulnerability identified as CVE-2009-4917 affects Cisco Adaptive Security Appliances (ASA) 5580 series devices operating with software versions prior to 8.1(2). This represents a significant security flaw that enables remote attackers to execute a denial of service attack by overwhelming the affected devices with substantial volumes of Session Initiation Protocol traffic. The issue manifests as an unexpected device reload, effectively disrupting network services and compromising availability for legitimate users.
The technical nature of this vulnerability stems from insufficient input validation and processing capabilities within the ASA device's SIP handling mechanisms. When subjected to high-volume SIP traffic, the device fails to properly manage the incoming data streams, leading to resource exhaustion or buffer overflows that ultimately trigger a system restart. This behavior aligns with CWE-122, which describes buffer overflow conditions, and CWE-400, which covers resource exhaustion vulnerabilities. The flaw demonstrates inadequate state management and traffic processing controls that are essential for maintaining system stability under stress conditions.
From an operational perspective, this vulnerability presents a critical risk to organizations relying on Cisco ASA 5580 series appliances for network security. The remote exploitation capability means that attackers can initiate the denial of service attack from outside the network perimeter without requiring local access or authentication credentials. The impact extends beyond simple service disruption as the device reload can result in temporary loss of network security protection, potentially exposing the network to additional threats during the recovery period. Organizations may experience extended downtime while the device reboots and reestablishes network connections, with potential cascading effects on dependent services and applications.
The attack vector for this vulnerability specifically targets the Session Initiation Protocol processing capabilities of the ASA device, making it particularly dangerous for environments where SIP traffic is common such as voice over IP implementations, unified communications systems, and telephony networks. The vulnerability affects the device's ability to handle legitimate SIP signaling traffic while simultaneously being vulnerable to malicious traffic flooding, creating a scenario where normal operations are disrupted by crafted attack traffic. This aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how a specific protocol implementation flaw can be weaponized for availability compromise.
Organizations should immediately implement mitigation strategies including applying the relevant Cisco security patches and software updates to reach version 8.1(2) or later. Network administrators should also consider implementing rate limiting and traffic filtering rules specifically targeting SIP traffic to reduce the impact of potential attacks. The implementation of intrusion detection systems capable of identifying and blocking anomalous SIP traffic patterns provides an additional layer of defense. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of affected devices within the network infrastructure. Additionally, maintaining detailed incident response procedures for handling device reload events ensures rapid recovery and minimizes business disruption during potential attack scenarios.