CVE-2008-0527 in Skinny Client Control Protocol
Summary
by MITRE
The HTTP server in Cisco Unified IP Phone 7935 and 7936 running SCCP firmware allows remote attackers to cause a denial of service (reboot) via a crafted HTTP request.
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Analysis
by VulDB Data Team • 08/05/2019
The vulnerability identified as CVE-2008-0527 affects the HTTP server implementation within Cisco Unified IP Phone 7935 and 7936 devices that operate with SCCP firmware. These telephony devices are part of Cisco's unified communications portfolio and serve as voice communication endpoints in enterprise environments. The flaw exists in the web server component that handles HTTP requests, which forms part of the device's management interface and web-based configuration capabilities.
This vulnerability represents a classic buffer overflow condition or input validation flaw within the HTTP server module. The device fails to properly validate or sanitize incoming HTTP requests, allowing remote attackers to craft malicious requests that trigger unexpected behavior in the underlying software stack. The specific nature of the flaw enables an attacker to send carefully constructed HTTP requests that cause the device to crash and subsequently reboot, effectively creating a denial of service condition that disrupts voice communications.
The operational impact of this vulnerability extends beyond simple service disruption as it affects critical communication infrastructure within enterprise networks. When the affected phones reboot repeatedly, it creates communication outages that can severely impact business operations, particularly in environments where voice communication is mission-critical. The remote nature of the attack means that adversaries do not require physical access or network credentials to exploit the vulnerability, making it particularly dangerous in unsecured network environments where these devices might be directly accessible from external networks.
From a cybersecurity perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how embedded network devices can contain exploitable flaws that affect their operational integrity. The ATT&CK framework categorizes this as a denial of service attack vector, specifically falling under the technique of service stoppage or system reboot. Network administrators and security teams must consider this vulnerability as part of their broader threat landscape, particularly when assessing the security posture of unified communications systems.
Mitigation strategies for this vulnerability should include immediate firmware updates from Cisco that address the HTTP server implementation flaw. Organizations should also implement network segmentation to isolate these devices from external networks and restrict access through proper access controls. Additional protective measures include monitoring network traffic for suspicious HTTP request patterns, implementing intrusion detection systems, and ensuring that default administrative credentials are changed. The vulnerability highlights the importance of maintaining up-to-date security patches for network infrastructure devices and demonstrates the critical need for proper input validation in embedded systems. Organizations should also consider network access controls that limit HTTP server access to trusted administrative networks only, reducing the attack surface for such remote exploitation opportunities.