CVE-2014-7912 in Android
Summary
by MITRE
The get_option function in dhcp.c in dhcpcd before 6.2.0, as used in dhcpcd 5.x in Android before 5.1 and other products, does not validate the relationship between length fields and the amount of data, which allows remote DHCP servers to execute arbitrary code or cause a denial of service (memory corruption) via a large length value of an option in a DHCPACK message.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/07/2022
The vulnerability identified as CVE-2014-7912 represents a critical buffer overflow condition within the dhcpcd DHCP client implementation that affects multiple Android versions and various network infrastructure products. This flaw exists in the get_option function located within dhcp.c, specifically in dhcpcd versions prior to 6.2.0. The vulnerability stems from inadequate validation of DHCP option data structures where the software fails to properly verify the relationship between length fields and the actual data payload within DHCPACK messages. Remote attackers can exploit this weakness by crafting malicious DHCPACK responses containing oversized option length values that exceed the allocated buffer space, potentially leading to memory corruption and arbitrary code execution.
The technical nature of this vulnerability aligns with CWE-129, which addresses insufficient validation of length fields, and represents a classic buffer overflow scenario where the software does not validate that option data lengths do not exceed the allocated memory boundaries. The flaw operates at the network protocol parsing layer where DHCP client implementations process received configuration messages from DHCP servers. When the get_option function processes a DHCPACK message, it reads the option length field and attempts to allocate or access memory based on this value without proper bounds checking. This creates a scenario where an attacker-controlled value can dictate memory access patterns, potentially causing stack corruption, heap corruption, or other memory-related vulnerabilities that may be exploited to execute arbitrary code.
The operational impact of CVE-2014-7912 extends across multiple Android versions, specifically affecting Android 4.x releases prior to version 5.1, making it particularly dangerous in mobile environments where devices frequently connect to untrusted networks. The vulnerability allows for remote code execution, which aligns with ATT&CK technique T1059.007 for command and script injection, and can also result in denial of service conditions that render network connectivity unusable. In practical attack scenarios, an attacker positioned on the same network segment can send specially crafted DHCPACK messages that trigger the buffer overflow, potentially compromising the entire device. The attack vector is particularly concerning because it requires minimal privileges and can be executed against any device that accepts DHCP responses, making it a significant threat in both enterprise and consumer environments where mobile devices and embedded systems are prevalent.
Mitigation strategies for this vulnerability should focus on immediate software updates to dhcpcd version 6.2.0 or later, which includes proper bounds checking for DHCP option lengths. Network administrators should also implement DHCP snooping and other network access controls to limit the ability of unauthorized devices to inject malicious DHCP responses. Additionally, organizations should consider implementing network segmentation and monitoring to detect anomalous DHCP traffic patterns that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation in network protocol implementations and highlights the need for comprehensive security testing of network client applications that process untrusted network data, particularly in mobile and embedded environments where such clients are commonly deployed.