CVE-2016-10340 in Android
Summary
by MITRE
In all Android releases from CAF using the Linux kernel, an integer underflow leading to buffer overflow vulnerability exists in a syscall handler.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2016-10340 represents a critical security flaw affecting all Android releases that utilize the Linux kernel from Code Aurora Forum. This vulnerability manifests within the system call handler mechanism where an integer underflow condition can occur, ultimately leading to a buffer overflow scenario. The flaw exists at the kernel level and affects the foundational operating system components that Android relies upon for its core functionality.
The technical implementation of this vulnerability stems from improper input validation within the kernel's system call handling code. When processing specific system calls, the kernel fails to adequately validate integer values that are used to determine buffer sizes or array indices. This allows malicious actors to manipulate input parameters such that integer underflow occurs, where a signed integer operation results in a value that is smaller than the minimum representable value. The underflow condition subsequently propagates into a buffer overflow situation where memory beyond the intended buffer boundaries gets overwritten.
From an operational perspective, this vulnerability presents a severe risk to Android devices since it operates at the kernel level and can be exploited through legitimate system call interfaces. Attackers can potentially leverage this flaw to execute arbitrary code with kernel privileges, effectively bypassing the security model that separates user-space applications from the core operating system. The implications extend beyond simple privilege escalation, as this vulnerability can be used to compromise the entire device, potentially enabling full system takeover, data exfiltration, and persistent backdoor installation.
The vulnerability aligns with CWE-191, which specifically addresses integer underflow conditions, and demonstrates characteristics consistent with the ATT&CK framework's privilege escalation techniques. The exploitability of this vulnerability is enhanced by the fact that it requires no special privileges to trigger, making it particularly dangerous as it can be exploited through normal system operations. The buffer overflow component of this vulnerability also relates to CWE-121, which covers stack-based buffer overflow conditions, and can be used to manipulate kernel memory structures and execute malicious code.
Mitigation strategies for CVE-2016-10340 require immediate patching of affected kernel versions through security updates provided by device manufacturers and Google. Organizations should implement comprehensive monitoring of their Android device fleets to identify affected systems and ensure timely deployment of security patches. Additional protective measures include enabling kernel address space layout randomization, implementing strict input validation controls, and maintaining up-to-date security configurations that limit the attack surface. Device manufacturers should also conduct thorough security testing of kernel modifications and maintain robust vulnerability management processes to prevent similar issues from emerging in future releases.