CVE-2023-2019 in Linux
Summary
by MITRE • 04/25/2023
A flaw was found in the Linux kernel's netdevsim device driver, within the scheduling of events. This issue results from the improper management of a reference count. This may allow an attacker to create a denial of service condition on the system.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/17/2025
The vulnerability identified as CVE-2023-2019 resides within the Linux kernel's netdevsim device driver, representing a critical flaw that impacts system stability and availability. The netdevsim driver serves as a virtual network device simulator used primarily for testing and development purposes, allowing developers to simulate network devices without physical hardware. This particular vulnerability manifests in the improper management of reference counts during event scheduling operations, creating a potential attack vector that could compromise system integrity.
The technical root cause of this vulnerability stems from inadequate reference count handling within the event scheduling mechanism of the netdevsim driver. When events are scheduled and processed, the driver fails to properly maintain reference count semantics, leading to situations where resources may be prematurely released or double-freed. This mismanagement creates a race condition scenario where concurrent access to shared resources can result in undefined behavior. The flaw specifically aligns with CWE-476 which addresses NULL pointer dereferences and improper resource management patterns. The vulnerability enables an attacker to manipulate the reference counting logic through controlled inputs, potentially causing the kernel to execute invalid memory operations or enter an inconsistent state.
From an operational perspective, this vulnerability presents a significant denial of service risk that could affect any system running the affected Linux kernel version with the netdevsim driver enabled. The attack surface is particularly concerning because the netdevsim driver is often present in development environments and testing frameworks where attackers might have limited access to system resources. An attacker could exploit this flaw by triggering specific sequences of events that cause the reference count to reach invalid states, leading to kernel panics, system crashes, or complete system unresponsiveness. The impact extends beyond simple service disruption as such vulnerabilities in kernel drivers can potentially provide footholds for more sophisticated attacks or enable privilege escalation attempts.
Mitigation strategies for CVE-2023-2019 should prioritize immediate kernel updates from vendors, as the most effective solution involves applying the patched kernel version that corrects the reference count management logic. System administrators should also consider disabling the netdevsim driver entirely if it is not required for production environments, using the command modprobe -r netdevsim to remove the module from active memory. Additionally, implementing proper access controls and monitoring for unusual event scheduling patterns can help detect potential exploitation attempts. The vulnerability demonstrates the importance of proper resource management in kernel space operations and aligns with ATT&CK technique T1499 which covers network denial of service attacks. Organizations should also conduct regular security assessments of their kernel components and maintain up-to-date patch management procedures to prevent similar issues from compromising system availability and stability.