CVE-2018-14634 in Linux
Summary
by MITRE
An integer overflow flaw was found in the Linux kernel's create_elf_tables() function. An unprivileged local user with access to SUID (or otherwise privileged) binary could use this flaw to escalate their privileges on the system. Kernel versions 2.6.x, 3.10.x and 4.14.x are believed to be vulnerable.
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Analysis
by VulDB Data Team • 03/19/2026
The vulnerability identified as CVE-2018-14634 represents a critical integer overflow flaw within the Linux kernel's create_elf_tables() function that fundamentally undermines system security through privilege escalation mechanisms. This flaw exists at the kernel level where the system processes ELF (Executable and Linkable Format) binary tables during program execution, creating a pathway for malicious exploitation that directly targets the core operating system functionality. The vulnerability specifically affects kernel versions spanning 2.6.x, 3.10.x, and 4.14.x, indicating a widespread impact across multiple kernel branches that have been in production use for years. The integer overflow occurs when processing certain binary formats, particularly those with SUID (Set User ID) permissions, which allows unprivileged users to leverage this flaw for unauthorized privilege elevation.
The technical implementation of this vulnerability stems from improper input validation within the kernel's ELF table creation logic where integer arithmetic operations exceed the maximum representable value for the data type being used. When an attacker executes a specially crafted SUID binary, the kernel's create_elf_tables() function processes the binary's memory layout and environment variables without adequate bounds checking. This overflow condition can result in memory corruption that allows an attacker to manipulate kernel data structures or overwrite critical system components. The flaw is particularly dangerous because it operates within the kernel's memory management subsystem, where successful exploitation can grant attackers full system control without requiring prior authentication or elevated privileges. The vulnerability falls under CWE-190, Integer Overflow or Wraparound, which specifically addresses the improper handling of integer arithmetic operations that exceed the maximum value that can be represented by the data type.
The operational impact of CVE-2018-14634 extends far beyond simple privilege escalation, as it provides attackers with a persistent foothold that can be leveraged for further system compromise. Once an unprivileged user successfully exploits this vulnerability, they gain the ability to execute arbitrary code with kernel-level privileges, effectively bypassing all standard security controls and access restrictions. This capability enables attackers to install rootkits, modify system binaries, access sensitive data, and establish backdoors that persist across system reboots. The vulnerability's exploitation aligns with ATT&CK technique T1068, Exploitation for Privilege Escalation, and can be chained with other techniques to achieve comprehensive system compromise. The widespread kernel version affected means that organizations running these kernel versions across servers, workstations, and embedded systems face significant risk, particularly in environments where SUID binaries are prevalent and where users may have access to such binaries through legitimate system usage patterns.
Organizations must implement immediate mitigation strategies to address this vulnerability, beginning with kernel updates to versions that contain the patched create_elf_tables() function with proper integer overflow protections. The recommended approach involves deploying security patches from trusted sources such as the Linux kernel security team, ensuring that all affected kernel versions are updated to prevent exploitation. System administrators should also consider implementing additional security controls including monitoring for suspicious SUID binary execution, employing kernel hardening techniques such as stack canaries and address space layout randomization, and conducting regular vulnerability assessments to identify potentially affected systems. The mitigation strategy should include disabling unnecessary SUID binaries where possible and implementing strict access controls to limit user exposure to potentially vulnerable system components. Additionally, organizations should establish incident response procedures specifically designed to handle privilege escalation vulnerabilities, as the exploitation of such flaws often indicates a broader compromise attempt that requires comprehensive forensic analysis and system hardening measures.