CVE-2014-6417 in Linux
Summary
by MITRE • 01/25/2023
net/ceph/auth_x.c in Ceph, as used in the Linux kernel before 3.16.3, does not properly consider the possibility of kmalloc failure, which allows remote attackers to cause a denial of service (system crash) or possibly have unspecified other impact via a long unencrypted auth ticket.
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Analysis
by VulDB Data Team • 01/25/2023
The vulnerability described in CVE-2014-6417 affects the Ceph distributed storage system implementation within the Linux kernel version prior to 3.16.3. This issue resides in the net/ceph/auth_x.c file where the authentication mechanism fails to properly handle memory allocation failures during the processing of authentication tickets. The flaw represents a classic memory management error that can be exploited to disrupt system operations through a denial of service attack.
The technical root cause of this vulnerability stems from inadequate error handling in the kernel's memory allocation functions, specifically kmalloc which is responsible for allocating memory in the kernel space. When processing long unencrypted authentication tickets, the system attempts to allocate memory for processing these tickets without sufficient validation of allocation success. This creates a scenario where a malicious remote attacker can craft specially crafted authentication tickets that trigger memory allocation failures, leading to system instability.
From an operational perspective, this vulnerability presents significant risks to systems relying on Ceph storage clusters, particularly in enterprise environments where storage availability is critical. The denial of service impact can result in complete system crashes, forcing administrators to restart services or entire systems, potentially causing data unavailability and service disruption. Additionally, the unspecified other impacts mentioned in the CVE description suggest there may be potential for more severe consequences including privilege escalation or information disclosure, though these remain unconfirmed.
The vulnerability aligns with CWE-704, which addresses improper handling of memory allocation failures in kernel space, and demonstrates characteristics consistent with ATT&CK technique T1499.004 for network denial of service attacks. The attack surface is particularly concerning as it requires only remote access to potentially exploit the vulnerability, making it accessible to attackers without physical presence or elevated privileges. The long unencrypted auth ticket mechanism serves as the attack vector, allowing malicious actors to send oversized authentication data that exceeds normal processing limits.
Mitigation strategies for this vulnerability include applying the kernel patch released with version 3.16.3, which implements proper error handling for memory allocation failures in the authentication subsystem. System administrators should also consider implementing network segmentation and access controls to limit exposure to untrusted networks. Monitoring for unusual authentication ticket sizes and implementing intrusion detection systems can help identify potential exploitation attempts. Additionally, organizations should maintain updated security patches and conduct regular vulnerability assessments to ensure comprehensive protection against similar memory management flaws in storage subsystems.