CVE-2023-2602: Security Advisory - Vulnerability in pthread_create() function in libcap leading to Potential Memory Exhaustion

Researchers have discovered a vulnerability impacting the pthread_create() function in the libcap library. This security flaw, identified as CVE-2023-2602, has the potential to be exploited by malicious actors, allowing them to cause the __real_pthread_create() function to return an error, ultimately leading to the exhaustion of process memory. The importance of understanding and mitigating this vulnerability cannot be overstated, as it has serious implications for the proper functioning and security of affected systems.

Background

The libcap library is a key component of many applications, providing support for POSIX.1e capabilities in Linux. The pthread_create() function in this library is responsible for creating a new thread within a process, often used in multi-threaded applications to manage parallel tasks effectively. In the event of a successful exploitation of CVE-2023-2602, the functionality of this critical process is severely compromised.

Exploit Details

The vulnerability lies in the improper handling of the error returned by the __real_pthread_create() function. Attackers may invoke this error with crafted input, forcing the application to exhaust its process memory. As a result, the affected system could experience severe performance degradation or even a complete shutdown.

The following code snippet illustrates the vulnerability within the pthread_create() function

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>

void * working_thread(void *arg)
{
  printf("New thread created.\n");
  return NULL;
}

int main()
{
  pthread_t thread;
  int result;

  result = pthread_create(&thread, NULL, working_thread, NULL);
  if (result != ) {
    perror("Error encountered:");
    exit(EXIT_FAILURE);
  }

  printf("Main thread finished.\n");
  exit(EXIT_SUCCESS);
}

In the sample code provided, if the pthread_create() function returns an error, the application will terminate, as there is no mechanism in place to efficiently handle this error. Given the right circumstances, a malicious attacker could take advantage of this vulnerability by causing the function to return an error and force the application to repeatedly consume memory resources.

References

- Official CVE Listing: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-2602
- libcap GitHub Repository: https://github.com/YKnowledge/libcap

Mitigations

Since this vulnerability has the potential to cause significant damage, the urgency to address it is imperative. The following are suggestions to protect systems against CVE-2023-2602:

1. Always keep software up to date: Ensure that all software components are running the latest version, especially the libcap library.
2. Proper error handling: Implement robust error handling mechanisms within the application to prevent the program from crashing or consuming too much memory upon encountering an error.
3. Regular security assessments: Regularly review system and application security, adhering to best practices to minimize risk.

Conclusion

The discovery of CVE-2023-2602 highlights the need for ongoing vigilance in software security, particularly when dealing with critical components such as the pthread_create() function within the libcap library. Making use of the recommended mitigations will assist in ensuring that systems do not fall victim to malicious actors exploiting this vulnerability.

Timeline

Published on: 06/06/2023 20:15:00 UTC
Last modified on: 06/14/2023 18:07:00 UTC