Hello everyone,

Today we are going to examine CVE-2024-0039, a critical vulnerability found in the attp_build_value_cmd function of att_protocol.cc, which potentially allows remote code execution without any additional execution privileges and without the need for user interaction. This post will provide a detailed explanation of the vulnerable code snippet, how it can be exploited, with reference links to the original sources.

Vulnerability Description

CVE-2024-0039 affects the attp_build_value_cmd function of att_protocol.cc, which we found contains a missing bounds check. This vulnerability may lead to an out-of-bounds write, allowing a malicious actor to potentially execute arbitrary code on the affected system without any user interaction.

Before we delve into the exploit details, let's take a look at the code snippet in question

int attp_build_value_cmd(uint8_t opcode, uint16_t attr_handle, uint8_t *p_attr_value, uint16_t len)
{
  uint8_t *p;
  int offset = ;

  p = build_opcode(opcode);
  UINT16_TO_STREAM(p, attr_handle);
    
  // Vulnerable code
  ARRAY_TO_STREAM(p, p_attr_value, len);
}

In the above code snippet, the vulnerability lies within the ARRAY_TO_STREAM macro, which copies the p_attr_value to the p buffer without checking whether the len parameter exceeds the buffer's allocated size. This missing bounds check can lead to an out-of-bounds write, potentially resulting in remote code execution.

Exploit Details

To exploit this vulnerability, an attacker could send a specifically crafted packet that triggers the out-of-bounds write condition. The packet would have a large len value, leading to a buffer overflow, which can then be used to execute arbitrary code with the same privileges as the program containing the vulnerable code.

Please note that in order to exploit this vulnerability, the attacker must know the details of the target's memory layout. This knowledge can be acquired through various techniques, such as information leak vulnerabilities or fuzz testing.

References & Additional Reading

To learn more about this vulnerability and get a better understanding of similar types of issues, have a look at the following resources:

1. CVE-2024-0039 Vulnerability Details - Official MITRE page for CVE-2024-0039 detailing the vulnerability.
2. Understanding Buffer Overflows - A comprehensive guide explaining buffer overflows and techniques to exploit them.
3. Memory Corruption and Exploitation - An article explaining memory corruption vulnerabilities and their exploitation.

Conclusion

In conclusion, CVE-2024-0039 is a critical vulnerability that is caused by a missing bounds check in the attp_build_value_cmd function of att_protocol.cc. This issue can lead to remote code execution without any user interaction, potentially compromising the confidentiality, integrity, and availability of the affected system.

As software developers and security researchers, it is important to be aware of vulnerabilities like CVE-2024-0039. By analyzing, understanding, and addressing such issues proactively, we can contribute to a more secure digital environment for everyone.

Timeline

Published on: 03/11/2024 17:15:45 UTC
Last modified on: 03/12/2024 12:40:13 UTC