CVE-2023-5178 in Linux
Summary
by MITRE • 11/01/2023
A use-after-free vulnerability was found in drivers/nvme/target/tcp.c` in `nvmet_tcp_free_crypto` due to a logical bug in the NVMe/TCP subsystem in the Linux kernel. This issue may allow a malicious user to cause a use-after-free and double-free problem, which may permit remote code execution or lead to local privilege escalation.
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Analysis
by VulDB Data Team • 06/20/2025
The vulnerability identified as CVE-2023-5178 represents a critical use-after-free condition within the Linux kernel's NVMe/TCP subsystem, specifically in the drivers/nvme/target/tcp.c file at the nvmet_tcp_free_crypto function. This flaw exists within the NVMe over Fabrics target implementation that handles TCP transport connections for non-volatile memory express storage devices. The vulnerability stems from a logical error in the cryptographic context cleanup process where memory allocated for cryptographic operations is freed prematurely while still being referenced by other components of the NVMe/TCP target stack. The NVMe/TCP protocol enables remote access to local NVMe storage devices over network connections, making this vulnerability particularly dangerous as it can be exploited through network-based attacks against systems running the affected kernel versions.
The technical exploitation of this vulnerability occurs when malicious actors send specially crafted NVMe/TCP protocol messages that trigger the faulty memory management sequence in the nvmet_tcp_free_crypto function. When the kernel processes these malformed requests, the logical bug causes the system to free cryptographic memory structures while they remain in use by ongoing operations or pending references within the target subsystem. This creates both use-after-free and double-free conditions that can be leveraged by attackers to corrupt memory layout and potentially execute arbitrary code with kernel privileges. The vulnerability affects systems that implement NVMe/TCP target functionality, particularly those running Linux kernel versions that have not received the relevant security patches. The flaw demonstrates characteristics consistent with CWE-416 Use After Free and CWE-415 Double Free vulnerability classes, where improper memory management leads to exploitable conditions in kernel space.
The operational impact of CVE-2023-5178 extends beyond simple system instability to encompass potential remote code execution and local privilege escalation capabilities. An attacker who successfully exploits this vulnerability can gain full control over the affected system, potentially leading to complete compromise of storage infrastructure and data access. The vulnerability affects systems that serve NVMe/TCP targets, including storage servers, data center infrastructure, and any system that exposes NVMe storage devices over TCP networks. This makes it particularly concerning for enterprise environments where storage systems are exposed to untrusted networks or where attackers may have network access to storage infrastructure. The attack surface includes any system running Linux kernel versions containing the vulnerable NVMe/TCP target code, with potential exploitation occurring through network connections without requiring authentication or local access to the target system.
Mitigation strategies for CVE-2023-5178 focus primarily on applying the relevant kernel security patches released by Linux kernel maintainers and distribution vendors. System administrators should prioritize updating their kernel versions to include the fixes that address the memory management logic in the nvmet_tcp_free_crypto function. Additionally, network segmentation and access controls should be implemented to limit exposure of systems running NVMe/TCP targets to trusted networks only, reducing the attack surface for potential exploitation. Monitoring for unusual network traffic patterns related to NVMe/TCP protocol communications can help detect potential exploitation attempts. Organizations should also consider implementing kernel lockdown mechanisms and other security hardening measures that can limit the impact of successful exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as successful exploitation could enable attackers to execute arbitrary code with kernel privileges and escalate their access level within the affected systems.