CVE-2016-1469 in SPA300
Summary
by MITRE
The HTTP framework on Cisco SPA300, SPA500, and SPA51x devices allows remote attackers to cause a denial of service (device outage) via a series of malformed HTTP requests, aka Bug ID CSCut67385.
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Analysis
by VulDB Data Team • 09/15/2022
The vulnerability identified as CVE-2016-1469 affects Cisco Small Business Phone System devices including SPA300, SPA500, and SPA51x series phones. This flaw resides within the HTTP framework of these telephony devices, creating a remote denial of service condition that can result in complete device outage. The vulnerability represents a critical security weakness that allows unauthorized remote attackers to exploit the device's web server functionality through carefully crafted malformed HTTP requests. The specific bug identifier CSCut67385 indicates this was tracked within Cisco's internal vulnerability management system, highlighting the organization's recognition of the severity and impact of this issue.
The technical implementation of this vulnerability stems from inadequate input validation within the HTTP request processing component of the affected Cisco devices. When these devices receive malformed HTTP requests containing malformed headers, unexpected content lengths, or other irregularities in the HTTP protocol structure, the device's web server fails to properly handle these malformed inputs. This failure leads to a cascading system instability where the device's HTTP service becomes unresponsive, ultimately causing the entire device to become unavailable. The flaw demonstrates poor error handling and resource management within the device's embedded web server implementation, which lacks proper bounds checking and input sanitization mechanisms.
The operational impact of CVE-2016-1469 extends beyond simple service disruption, as it can result in complete communication outages for organizations relying on these devices for voice communications. When exploited, the vulnerability can cause devices to crash or reboot repeatedly, leading to extended periods of unavailability that can severely impact business operations. Network administrators may experience difficulty maintaining consistent communication services, particularly in environments where these devices serve as primary voice endpoints. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter, making it particularly dangerous for organizations without proper network segmentation or firewall controls. This vulnerability directly maps to CWE-129, which describes improper validation of input boundaries, and aligns with ATT&CK technique T1499.004 for network denial of service attacks.
Organizations affected by this vulnerability should implement immediate mitigations including network segmentation to isolate these devices from untrusted networks, applying available Cisco security patches and firmware updates, and configuring firewall rules to restrict HTTP access to these devices. Network administrators should also consider disabling HTTP services entirely if they are not required for device management purposes. The recommended approach involves monitoring network traffic for suspicious HTTP request patterns and implementing intrusion detection systems to identify potential exploitation attempts. Additionally, organizations should verify that their devices are running the latest firmware versions that contain the specific fixes for this vulnerability, as Cisco has released patches addressing the underlying HTTP framework flaws. These mitigation strategies help reduce the attack surface and prevent unauthorized exploitation while maintaining necessary device functionality for legitimate network operations.