CVE-2016-1327 in DPC2203
Summary
by MITRE
Buffer overflow in the web server on Cisco DPC2203 and EPC2203 devices with firmware r1_customer_image allows remote attackers to execute arbitrary code via a crafted HTTP request, aka Bug ID CSCuv05935.
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Analysis
by VulDB Data Team • 07/10/2022
The vulnerability identified as CVE-2016-1327 represents a critical buffer overflow flaw within the web server component of Cisco DPC2203 and EPC2203 cable modem devices. This vulnerability specifically affects firmware versions including the r1_customer_image release and creates a remote code execution vector that can be exploited by attackers without authentication. The flaw exists in the handling of HTTP requests within the device's web server implementation, making it particularly dangerous as it can be triggered through standard web browsing activities. The vulnerability impacts a significant number of consumer and small business network devices that rely on Cisco's cable modem infrastructure for internet connectivity.
The technical implementation of this buffer overflow occurs when the web server processes specially crafted HTTP requests that exceed the allocated buffer space in memory. According to CWE classification, this represents a classic buffer overflow vulnerability categorized under CWE-121, which deals with stack-based buffer overflow conditions. The flaw manifests when the device fails to properly validate input length before copying data into fixed-size buffers, allowing attackers to overwrite adjacent memory locations. This memory corruption can be leveraged to overwrite return addresses, function pointers, or other critical program state information, ultimately enabling arbitrary code execution. The vulnerability is particularly concerning because it operates at the application layer of the network stack, where the web server interface is accessible to external attackers.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete device compromise and potential network infiltration. Successful exploitation allows attackers to gain full control over the affected devices, enabling them to modify network configurations, redirect traffic, install malicious software, or use the compromised devices as launching points for further attacks against the local network. From an ATT&CK framework perspective, this vulnerability maps to multiple techniques including T1059 for command and script execution, T1071 for application layer protocol usage, and T1082 for system information discovery. The vulnerability also facilitates lateral movement within networks as compromised devices can serve as pivot points for accessing other network resources. Network administrators face significant challenges in identifying and mitigating this threat due to the device's typical deployment in residential and small business environments where security monitoring may be limited.
Mitigation strategies for CVE-2016-1327 require immediate firmware updates from Cisco, as the company has released security patches addressing this specific vulnerability. Organizations should implement network segmentation to isolate affected devices from critical infrastructure, deploy intrusion detection systems to monitor for suspicious HTTP traffic patterns, and conduct thorough network scans to identify all affected devices. Network administrators should also consider disabling unnecessary web server functionality on these devices when possible, as this reduces the attack surface. The vulnerability demonstrates the importance of maintaining up-to-date firmware across all network infrastructure components and highlights the need for continuous security assessments of embedded systems. Additionally, implementing network access controls and monitoring for unusual traffic patterns can help detect exploitation attempts before they result in successful compromise of the affected devices.