CVE-2013-5532 in Unified IP Phone 9900
Summary
by MITRE
Buffer overflow in the web-application interface on Cisco 9900 IP phones allows remote attackers to cause a denial of service (webapp interface outage) via long values in unspecified fields, aka Bug ID CSCuh10343.
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Analysis
by VulDB Data Team • 05/13/2018
The vulnerability identified as CVE-2013-5532 represents a critical buffer overflow flaw within the web application interface of Cisco 9900 IP phones. This issue affects the device's ability to process input data through its web-based management interface, creating a potential avenue for remote exploitation. The vulnerability manifests when the system receives excessively long values in unspecified fields, which triggers memory corruption within the application's processing routines. Such buffer overflow conditions typically occur when programs write more data to a fixed-length buffer than it can accommodate, leading to overflows that may result in unpredictable behavior or system crashes.
The technical implementation of this vulnerability resides in the web application layer of the Cisco 9900 IP phone operating system, where input validation mechanisms fail to properly sanitize user-supplied data. When attackers supply maliciously crafted long values to unspecified fields within the web interface, the application's memory management routines become overwhelmed, causing the system to crash or become unresponsive. This behavior aligns with common buffer overflow patterns documented in the CWE (Common Weakness Enumeration) database under CWE-121, which describes heap-based buffer overflow conditions. The vulnerability's impact extends beyond simple system instability, as it can be leveraged to achieve complete denial of service against the affected device's web application interface, rendering the phone's management capabilities inaccessible to legitimate users.
From an operational perspective, this vulnerability presents significant risk to enterprise network environments that rely on Cisco 9900 IP phones for communication services. The remote nature of the attack means that threat actors can exploit the flaw from external networks without requiring physical access or authentication credentials, making it particularly dangerous for organizations with limited network segmentation. The denial of service condition affects the web application interface specifically, which typically provides administrators with essential configuration and monitoring capabilities for the phone system. This disruption can cascade into broader operational impacts, as network administrators lose the ability to manage or troubleshoot affected devices through their standard web-based interfaces. The vulnerability's classification under the ATT&CK framework would align with the T1499.004 technique for Network Denial of Service, as it specifically targets network device availability through application-level exploitation.
Mitigation strategies for CVE-2013-5532 should prioritize immediate implementation of Cisco's security patches and firmware updates, which address the underlying buffer overflow conditions in the web application interface. Network administrators should consider implementing additional security controls such as restricting access to the phone's web interface through firewall rules and network segmentation, limiting the attack surface available to potential threat actors. The implementation of intrusion detection systems capable of identifying anomalous traffic patterns associated with buffer overflow exploitation attempts can provide additional layers of defense. Organizations should also conduct regular vulnerability assessments to identify similar issues in other networked devices and ensure that input validation mechanisms are properly configured across all web applications. The remediation process should include thorough testing of updated firmware in controlled environments before deployment to production networks to prevent unintended service disruptions. Furthermore, maintaining comprehensive network monitoring capabilities enables rapid detection and response to exploitation attempts, while regular security awareness training for network administrators helps ensure proper configuration and maintenance practices are followed to prevent similar vulnerabilities from emerging in other system components.