CVE-2017-15274 in Linux
Summary
by MITRE
security/keys/keyctl.c in the Linux kernel before 4.11.5 does not consider the case of a NULL payload in conjunction with a nonzero length value, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) via a crafted add_key or keyctl system call, a different vulnerability than CVE-2017-12192.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/03/2023
The vulnerability described in CVE-2017-15274 represents a critical NULL pointer dereference flaw within the Linux kernel's key management subsystem. This issue exists in the security/keys/keyctl.c file and affects kernel versions prior to 4.11.5, making it a persistent threat across multiple kernel releases. The flaw specifically manifests when the kernel processes crafted system calls that attempt to add keys or manipulate keyctl operations with malformed parameters. The vulnerability is particularly concerning because it allows local attackers to trigger a kernel oops condition and subsequent system crash, effectively enabling a denial of service attack against the target system.
The technical root cause of this vulnerability stems from inadequate input validation within the key management system. When a crafted add_key or keyctl system call is executed with a NULL payload combined with a nonzero length value, the kernel's key handling code fails to properly validate the payload parameter before attempting to dereference it. This condition creates a scenario where the kernel attempts to access memory at a NULL address, leading to an immediate system crash. The vulnerability operates at the kernel level and requires local system access to exploit, making it a local privilege escalation vector that can be leveraged by any user with access to the system. This flaw is classified under CWE-476 as a NULL pointer dereference, which represents a fundamental programming error where a null pointer is accessed without proper validation.
The operational impact of CVE-2017-15274 extends beyond simple denial of service, as it can be exploited to destabilize critical system operations and potentially provide a foothold for further attacks. Attackers can repeatedly trigger this vulnerability to cause system instability, leading to service interruptions that may affect system availability and reliability. The vulnerability is particularly dangerous in environments where system stability is critical, such as enterprise servers, cloud infrastructure, or embedded systems that rely on consistent kernel operation. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1068 by providing a path for privilege escalation and system compromise through kernel-level exploits. The attack surface is relatively broad since any local user can potentially trigger this condition, making it a significant concern for system administrators managing multi-user environments.
Mitigation strategies for CVE-2017-15274 primarily focus on kernel version updates and system hardening measures. The most effective remediation involves upgrading to Linux kernel version 4.11.5 or later, where the vulnerability has been addressed through proper input validation and NULL pointer checks. System administrators should prioritize patching affected systems and implementing automated update mechanisms to ensure timely deployment of security fixes. Additionally, monitoring for suspicious system calls and implementing kernel security modules such as SELinux or AppArmor can help detect and prevent exploitation attempts. The vulnerability demonstrates the importance of robust input validation in kernel space code and highlights the necessity of thorough testing for edge cases in security-critical subsystems. Organizations should also consider implementing intrusion detection systems that can identify patterns of exploitation attempts and maintain comprehensive system logging to track potential abuse of this vulnerability.