CVE-2023-1382: Understanding the Data Race Flaw in Linux Kernel and Its Exploitation

A newly discovered security vulnerability within the Linux kernel has caught the attention of developers and system administrators alike. Designated as CVE-2023-1382, this data race flaw has been identified through meticulous research to affect specific parts of the kernel. In this long-read post, we will provide a detailed breakdown of the vulnerability, related code snippets, original references, and how exploits could be leveraged against vulnerable systems.

Vulnerability Overview

The vulnerability CVE-2023-1382 is a result of a data race flaw found in the Linux kernel, affecting the Transparent Inter-Process Communication (TIPC) protocol. It is specifically identified to occur between the allocation of the con variable and the point at which con->sock is set. In certain scenarios, this could lead to a NULL pointer dereference when attempting to access con->sock->sk in net/tipc/topsrv.c in the TIPC protocol.

The Linux kernel is responsible for handling millions of requests per second and enabling applications and hardware devices to function seamlessly. A vulnerability within the kernel codebase can have severe consequences ranging from crashes to unauthorized access to sensitive data.

The vulnerability occurs within the following code block in the file net/tipc/topsrv.c

static void topsrv_accept(struct tipc_conn *con)
{
  ...
  con = kzalloc(sizeof(*con), GFP_KERNEL);
  INIT_LIST_HEAD(&con->node);
  con->portid = tipc_get_portid(sock->sk); /* con->sock->sk */
  con->server = server;
  ...

The data race flaw occurs as con->sock is being accessed before it is assigned. This results in a NULL pointer dereference in the tipc_get_portid() call.

The original disclosure of the CVE-2023-1382 vulnerability can be found in the following resources

1. The official CVE entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1382
2. The National Vulnerability Database (NVD) entry: https://nvd.nist.gov/vuln/detail/CVE-2023-1382

Exploit Details

An attacker with access to a Linux-based system running a kernel version affected by CVE-2023-1382 could potentially carry out a local privilege escalation attack. This would allow the attacker to obtain unauthorized elevated privileges and compromise sensitive information on the system. This vulnerability may also lead to a denial-of-service attack, crashing the target machine.

Mitigation

As a system administrator or developer, the most effective way to protect your Linux-based system from potential CVE-2023-1382 exploitation is to update the kernel to the latest available version. Linux kernel developers regularly release patches in response to identified vulnerabilities, and timely updates can ensure the continued security of your system.

Conclusion

In summary, CVE-2023-1382 is a data race vulnerability affecting the TIPC protocol implementation within the Linux kernel. This flaw, if exploited, can cause a system crash or lead to unauthorized elevated privileges. By understanding the issue and applying kernel updates as needed, system administrators and developers can effectively protect their Linux environments from this vulnerability and similar security risks.

Timeline

Published on: 04/19/2023 23:15:00 UTC
Last modified on: 04/28/2023 03:49:00 UTC