CVE-2014-9914 in Linux
Summary
by MITRE • 01/25/2023
Race condition in the ip4_datagram_release_cb function in net/ipv4/datagram.c in the Linux kernel before 3.15.2 allows local users to gain privileges or cause a denial of service (use-after-free) by leveraging incorrect expectations about locking during multithreaded access to internal data structures for IPv4 UDP sockets.
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Analysis
by VulDB Data Team • 01/25/2023
The vulnerability described in CVE-2014-9914 represents a critical race condition affecting the Linux kernel's handling of IPv4 UDP socket operations. This flaw exists within the ip4_datagram_release_cb function located in the net/ipv4/datagram.c file, where improper locking mechanisms create opportunities for malicious exploitation. The vulnerability affects Linux kernel versions prior to 3.15.2, making it a significant concern for systems running older kernel versions that have not received the necessary security patches.
The technical implementation of this vulnerability stems from incorrect assumptions about locking behavior during multithreaded access to internal kernel data structures. When multiple threads attempt to access IPv4 UDP socket resources simultaneously, the kernel's locking mechanisms fail to properly protect shared resources, creating a window where one thread may attempt to access memory that another thread has already freed. This use-after-free condition occurs because the kernel expects certain locking guarantees that do not hold during concurrent socket operations, particularly when dealing with socket release callbacks.
The operational impact of this vulnerability manifests in two primary ways: privilege escalation and denial of service. Local attackers can exploit the race condition to execute arbitrary code with elevated privileges, potentially gaining root access to the affected system. The use-after-free condition allows attackers to manipulate kernel memory structures, leading to potential code execution in kernel space. Additionally, the vulnerability can cause system instability and denial of service conditions, where legitimate system operations may fail due to corrupted kernel memory or improper resource handling during concurrent socket operations.
From a cybersecurity perspective, this vulnerability aligns with CWE-362, which specifically addresses race conditions in concurrent programming, and represents a classic example of improper locking in kernel space operations. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting kernel-level attacks that leverage system-level race conditions. The vulnerability demonstrates how seemingly minor locking implementation details can create significant security implications, as the race condition allows for direct manipulation of kernel memory structures.
Mitigation strategies for CVE-2014-9914 primarily involve upgrading to Linux kernel versions 3.15.2 or later, where the race condition has been properly addressed through corrected locking mechanisms and improved synchronization primitives. System administrators should prioritize patching affected systems, particularly those running older kernel versions that may be exposed to local privilege escalation attacks. Additional defensive measures include implementing proper kernel hardening configurations, monitoring for unusual network activity patterns that might indicate exploitation attempts, and maintaining up-to-date security monitoring solutions that can detect anomalous behavior in kernel space operations. Organizations should also consider implementing network segmentation and access controls to limit local user access to systems that may be vulnerable to such attacks.