CVE-2016-1503 in Android
Summary
by MITRE
dhcpcd before 6.10.0, as used in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-04-01 and other products, mismanages option lengths, which allows remote attackers to execute arbitrary code or cause a denial of service (heap-based buffer overflow) via a malformed DHCP response, aka internal bug 26461634.
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Analysis
by VulDB Data Team • 07/12/2022
The vulnerability identified as CVE-2016-1503 represents a critical heap-based buffer overflow in the dhcpcd DHCP client implementation affecting multiple Android versions and other systems. This flaw exists in dhcpcd versions prior to 6.10.0 and specifically impacts Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before the specified date. The vulnerability stems from improper handling of DHCP option lengths during packet processing, creating a condition where maliciously crafted DHCP responses can trigger memory corruption. The technical implementation flaw manifests when the dhcpcd client processes malformed DHCP responses containing oversized or improperly formatted option fields, leading to buffer overflows in heap memory allocations. This vulnerability directly maps to CWE-121, heap-based buffer overflow, and aligns with ATT&CK technique T1059.007 for execution through command injection, though the specific vector here involves memory corruption rather than direct command execution.
The operational impact of this vulnerability extends across numerous Android devices and embedded systems that rely on dhcpcd for DHCP configuration. Remote attackers can exploit this weakness by positioning themselves on the same network segment as the vulnerable device and sending specially crafted DHCP responses containing malformed option data. The consequences include arbitrary code execution with the privileges of the dhcpcd process, which typically runs with elevated privileges, or denial of service conditions that can render network connectivity unusable. Given that dhcpcd is a core networking component in Android systems, successful exploitation can compromise device functionality and potentially provide attackers with persistent access to the network. The vulnerability affects not only Android devices but also other products using the same dhcpcd implementation, making it a widespread concern across various embedded and mobile platforms.
Mitigation strategies for CVE-2016-1503 require immediate patching of affected dhcpcd versions to 6.10.0 or later, which includes proper validation of DHCP option lengths and implementation of bounds checking mechanisms. Network administrators should consider implementing DHCP snooping and other network segmentation measures to limit the scope of potential attacks, though these are not complete solutions given the remote nature of the vulnerability. Device manufacturers and users should prioritize updating Android systems to versions that incorporate patched dhcpcd implementations, particularly focusing on the affected Android versions mentioned in the vulnerability description. Additionally, monitoring network traffic for suspicious DHCP responses and implementing intrusion detection systems that can identify malformed DHCP packets can provide early warning of attempted exploitation. The vulnerability highlights the importance of proper input validation in network protocol implementations and serves as a reminder of the critical security considerations required in embedded system components that handle network communications. Organizations should also conduct vulnerability assessments to identify other potentially affected systems using older dhcpcd versions and ensure comprehensive patch management processes are in place to address similar issues proactively.