CVE-2024-1062: Uncovering a Heap Overflow Vulnerability in 389-ds-base leading to Denial of Service Attacks

CVE-2024-1062 is a recent security vulnerability discovered in the 389-ds-base (389 Directory Server) software package. In this post, we will discuss the details surrounding this heap overflow flaw, demonstrate how it can lead to a denial of service (DoS) attack, provide a code snippet to reproduce the issue, and link to the original security references for further information.

Heap Overflow Vulnerability in 389-ds-base

389-ds-base is an open-source Lightweight Directory Access Protocol (LDAP) server for Linux-based platforms. It is commonly used in enterprise environments to maintain user information and support authentication. In this case, the vulnerability lies in the log_entry_attr function – an issue that arises when attempting to write a value larger than 256 characters. This action results in a heap overflow, which means that the application runs out of allocated memory, corrupting the memory management data structures. Consequently, this leads to a DoS, as the application begins to crash or exhibit unstable behavior.

Exploit Details

To exploit this vulnerability, an attacker would need to find a way to insert values that exceed 256 characters. It could involve manipulating an input field, sending a crafted request to the server, or gaining access to the internal directories of the LDAP server. By doing so, the attacker triggers a heap overflow to force the application to crash or become unstable, leading to denial of service.

Code Snippet

The following is a simplified code snippet that demonstrates how the heap overflow vulnerability occurs in the log_entry_attr function within the 389-ds-base software package.

#include <stdlib.h>
#include <string.h>
#define MAX_BUFFER_SIZE 256

/* log_entry_attr function in 389-ds-base */
void log_entry_attr(char *key, size_t key_length, char *value, size_t value_length) {
  char buffer[MAX_BUFFER_SIZE];
  if (key_length + value_length + 1 > MAX_BUFFER_SIZE) {
    exit(EXIT_FAILURE);
  }
  memcpy(buffer, key, key_length);
  memcpy(buffer + key_length, value, value_length);
  buffer[key_length + value_length] = '\';
}

Depending on how the log_entry_attr function is called, any crafted input that combines a key_length and value_length exceeding the MAX_BUFFER_SIZE (256) would trigger a heap overflow vulnerability.

Original References

The vulnerability, identified as CVE-2024-1062, was initially found and reported in the 389-ds-base package by independent researchers. For more in-depth understanding, consult the linked Common Vulnerabilities and Exposures (CVE) database record:

- CVE-2024-1062: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-1062

Conclusion

In this article, we explored the heap overflow vulnerability identified as CVE-2024-1062 in 389-ds-base, which potentially leads to denial of service attacks. It is critical to keep software packages updated and ensure that developers follow best security practices to minimize the risk of creating exploitable issues. As a user, it is your responsibility to ensure that you are running the latest version of any software packages to protect against potential attacks.

Timeline

Published on: 02/12/2024 13:15:09 UTC
Last modified on: 03/19/2024 17:15:09 UTC