The security vulnerability tracked under CVE-2023-0179 involves a buffer overflow bug in the Netfilter subsystem used in the Linux Kernel. This vulnerability can lead to potential leakage of both stack and heap addresses, which may facilitate a Local Privilege Escalation (LPE) attack for achieving root access to a target system via arbitrary code execution.

This in-depth analysis aims to provide an overview of the vulnerability, the underlying affected code, and how exploitation could occur. Additionally, we will discuss potential mitigation strategies to help limit the attack surface for this critical issue.

Vulnerability Overview: CVE-2023-0179

The buffer overflow vulnerability was discovered in the Netfilter subsystem in the Linux Kernel, a critical component responsible for network packet filtering, address translation, and other low-level network functions. The vulnerability exists due to an insufficient bounds check in the subsystem code.

A malicious user could leverage this vulnerability to perform a heap buffer overflow and eventually lead to LPE by executing arbitrary code with the root user's level of access.

Code Analysis: The Buffer Overflow Issue

To understand the vulnerability, let's review the code snippet responsible for the buffer overflow in the Netfilter subsystem. The affected code is found in the net/netfilter directory of the Linux Kernel source code. For demonstration purposes, let's consider the following example code:

/* Vulnerable code in net/netfilter/nf_conntrack_core.c */

int process_packet(struct sk_buff *skb, const struct nf_hook_state *state) {
  struct nf_conntrack_tuple tuple;
  nf_ct_get_tuplepr(skb, skb_network_offset(skb), state->pf, state->net, &tuple);

  u8 protocol = tuple.src.l3num;
  u8 size = (protocol == NFPROTO_IPV4) ? 4 : 16;

  u8 buffer[4];
  memcpy(buffer, tuple.src.u3.all, size);   // Buffer overflow vulnerability!

The vulnerability lies in the memcpy() function call. The memcpy() function copies size bytes of data from the source pointer tuple.src.u3.all to the destination buffer buffer. However, as the buffer is defined to contain only 4 bytes, copying more than 4 bytes will lead to a buffer overflow.

Identify a way to control the tuple.src.l3num value.

2. Craft a malicious network packet with the manipulated value to trigger the buffer overflow, and send it to the vulnerable system.
3. Use the leakage of stack and heap addresses from the buffer overflow to craft subsequent exploits targeting other kernel memory components, potentially leading to LPE and arbitrary code execution as the root user.

- CVE-2023-0179 - Official CVE Details
- Linux Kernel Source Code - Source Code Repository for the Linux Kernel

To prevent exploitation of this vulnerability, system administrators and developers are advised to

1. Patch the Linux Kernel on affected systems: The upcoming kernel release is expected to contain the security fix that addresses this vulnerability. Ensure that systems are updated to use the patched kernel version.
2. Implement strict network filtering: Configure network firewalls to block any suspicious or unknown traffic that may trigger exploitation of the vulnerability.
3. Monitor network traffic: Keep an eye on abnormal network packet patterns sent to the vulnerable systems, as this may indicate an attempt to exploit the vulnerability.
4. Apply Principle of Least Privilege: Limit the privileges of user accounts and services running on the system, ensuring that an attacker would require more effort to escalate privileges and execute arbitrary code as the root user.


CVE-2023-0179 is a critical buffer overflow vulnerability that affects the Netfilter subsystem in the Linux Kernel. If exploited, it could lead to the leakage of stack and heap memory addresses, as well as Local Privilege Escalation to the root user via arbitrary code execution. It is crucial for system administrators and developers to stay vigilant, implement mitigation strategies, and patch their affected systems as soon as possible to protect themselves from potential security breaches.


Published on: 03/27/2023 22:15:00 UTC
Last modified on: 04/07/2023 12:42:00 UTC