CVE-2014-3534 in Linux
Summary
by MITRE
arch/s390/kernel/ptrace.c in the Linux kernel before 3.15.8 on the s390 platform does not properly restrict address-space control operations in PTRACE_POKEUSR_AREA requests, which allows local users to obtain read and write access to kernel memory locations, and consequently gain privileges, via a crafted application that makes a ptrace system call.
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Analysis
by VulDB Data Team • 02/10/2022
The vulnerability described in CVE-2014-3534 represents a critical privilege escalation flaw within the Linux kernel's s390 architecture implementation. This issue specifically affects systems running Linux kernel versions prior to 3.15.8 on s390 platforms, which include IBM System/390 and z/Architecture mainframe systems. The vulnerability resides in the ptrace.c file within the kernel's s390 architecture-specific code, where improper validation of address-space control operations occurs during PTRACE_POKEUSR_AREA requests. This flaw fundamentally undermines the kernel's memory protection mechanisms and creates a pathway for local attackers to bypass critical security boundaries.
The technical implementation of this vulnerability stems from insufficient input validation within the ptrace system call handling code for the s390 architecture. When a process makes a PTRACE_POKEUSR_AREA request, the kernel should validate that the target memory addresses fall within the appropriate user-space boundaries and that the operation does not extend into kernel memory regions. However, the flawed implementation fails to properly restrict these operations, allowing malicious applications to specify arbitrary kernel memory addresses for read and write operations. This misconfiguration enables attackers to directly manipulate kernel data structures, registers, and memory locations that should remain protected from user-space access, effectively creating a backdoor into the kernel's protected memory space.
The operational impact of this vulnerability is severe and far-reaching for systems running affected kernel versions. Local users who can execute a crafted application with ptrace capabilities can leverage this flaw to gain kernel-level privileges, effectively achieving complete system compromise. The vulnerability enables attackers to read sensitive kernel memory locations, potentially exposing cryptographic keys, passwords, or other confidential data, while simultaneously allowing them to write to critical kernel structures. This dual capability of read and write access to kernel memory provides attackers with unprecedented control over system operations, potentially enabling them to modify kernel code, disable security mechanisms, or establish persistent backdoors. The impact extends beyond immediate privilege escalation as it undermines the fundamental security model of the operating system, potentially affecting all running processes and system services.
Mitigation strategies for CVE-2014-3534 primarily focus on immediate kernel updates to versions 3.15.8 or later, which contain the necessary patches to properly validate address-space control operations in ptrace requests. Organizations should prioritize applying these updates across all affected s390 systems, particularly in environments where local user access cannot be strictly controlled. Additional defensive measures include implementing strict process monitoring to detect suspicious ptrace activities and employing kernel hardening techniques such as disabling unnecessary ptrace capabilities for untrusted processes. The vulnerability aligns with CWE-122 (Heap-based Buffer Overflow) and CWE-125 (Out-of-bounds Read) categories, representing a classic case of improper input validation that leads to privilege escalation. From an ATT&CK framework perspective, this vulnerability maps to T1068 (Local Privilege Escalation) and T1548.001 (Abuse Elevation Control Mechanism) techniques, demonstrating how kernel-level flaws can be exploited to bypass operating system security controls. System administrators should also consider implementing monitoring solutions that can detect and alert on unusual ptrace system call patterns, as these activities may indicate exploitation attempts.