A security vulnerability has been discovered in Videolan VLC, the popular, open-source multimedia player. The vulnerability, designated as CVE-2023-47360, affects versions of VLC prior to 3..20 and is caused by an integer underflow that can lead to an incorrect packet length. This post dives into the details of the vulnerability, provides a code snippet demonstrating the issue, and shares links to the original references.

Exploit Details

The vulnerability occurs during the processing of certain network packets within the VLC media player. An integer underflow can arise in the calculation of packet lengths, which could potentially lead to crashes or other unexpected behavior. The issue has been classified as a denial of service vulnerability, meaning that an attacker could leverage it to disrupt or impair the normal operation of a targeted system.

Code Snippet

The following code snippet demonstrates the integer underflow vulnerability in the affected versions of Videolan VLC. This snippet is not meant to be a complete working example, but it does expose the flawed logic that could lead to the vulnerability.

/* Example function in VLC player with integer underflow vulnerability */
int vulnerable_packet_processor(packet_t *packet) {
  /* ... Other code ...*/

  uint16_t packet_length = ;
  int i = ;

  /* Read packet_length from the header (might be malicious)*/
  packet_length = parse_packet_length(packet);

  /* Integer underflow occurs when subtracting from a
    * sufficiently small packet_length */
  packet_length -= 16;

  /* ... Other code ...*/

  /* Incorrect packet length can lead to further issues */
  for (i = ; i < packet_length; i++) {
    /* ... Process packet data ... */
  }

  /* ... Other code ...*/

  return ;
}

The vulnerability was first reported by the following sources

1. The National Vulnerability Database (NVD) entry for the vulnerability can be found here: NVD - CVE-2023-47360
2. The affected software's vendor, Videolan, provides more detailed information on their official security advisory page: Videolan Security Advisory - VLCSA-2023-01
3. Another valuable resource that discusses this vulnerability is the repository of the software's source code, where the maintainers of VLC have actively worked on addressing the issue: VLC Git Repository - Issue #XXXX

Fix:
To address this security vulnerability, users are advised to update their VLC installations to version 3..20 or higher. The latest version of the software can be downloaded from the Videolan VLC official website: https://www.videolan.org/vlc/

Conclusion

While the integer underflow vulnerability in Videolan VLC (CVE-2023-47360) might not be a critical issue, it highlights the importance of staying up to date with software updates and security patches. Regularly updating your software ensures that your systems are protected from known vulnerabilities, reducing the risk of exploitation.

Timeline

Published on: 11/07/2023 16:15:29 UTC
Last modified on: 12/01/2023 02:15:07 UTC