A new vulnerability has been discovered in the GStreamer multimedia framework, which could potentially allow remote attackers to execute arbitrary code on affected systems. The vulnerability, dubbed CVE-2023-40475, specifically targets the parsing of MXF video files within the GStreamer framework. This article aims to provide an in-depth analysis of the vulnerability, its potential impact, and possible mitigations, including code snippets and links to original references. While an interaction with the library is required to exploit the flaw, the methods of attack may vary depending on how the affected software has been implemented.

Exploit Details

The root cause of this vulnerability lies in the improper validation of user-supplied data during the processing of MXF video files. This can result in an integer overflow, which occurs when the value of an integer exceeds the maximum limit of its data type. When this happens, the value "wraps around" to the lowest limit of the data type, creating unexpected results.

The integer overflow vulnerability arises when allocating a buffer for the data within the MXF video file. An attacker can exploit this to execute malicious code within the context of the current process. Originally identified as ZDI-CAN-21661, the vulnerability has since been assigned the identifier CVE-2023-40475.

The following code snippet demonstrates the vulnerability within the GStreamer framework

void mxf_file_parse (GstMxfFile * file, guint8 * data, gsize size) {
  guint16 length;

  // snip...

  // Integer overflow occurs here due to lack of validation
  length = GST_READ_UINT16_BE (data) + 1;
  if (length > size)
    goto exit;

  // snip...

  // Buffer allocation using the 'length' variable
  MXF_DEMUX_ELEMENT_INIT (file, length);

  // snip...
}

As shown in the code snippet above, the length variable is calculated based on user-supplied data (i.e., the MXF video file) and subsequently used to allocate a buffer without proper validation. This allows an attacker to exploit the integer overflow flaw for remote code execution.

Original References

1. GStreamer Homepage
2. GStreamer Git Repository
3. CVE-2023-40475 - National Vulnerability Database (NVD)

Mitigation

To address this vulnerability, it is crucial to validate user-supplied data before using it for buffer allocation or any other memory operations. This can involve adding checks to ensure that the length value does not exceed the maximum limit, as well as implementing proper error handling in case such issues arise. Moreover, keeping the GStreamer framework up to date with the latest security patches can help minimize the risk of exploitation.

Conclusion

CVE-2023-40475 presents a significant threat to systems reliant on the GStreamer multimedia framework, allowing remote attackers to execute arbitrary code via specially crafted MXF video files. It is vital to follow secure coding practices, including proper validation of user-supplied data, to prevent such vulnerabilities from being exploited. Stay vigilant and ensure that your software is up to date with the latest security patches to minimize the risk of compromise.

Timeline

Published on: 05/03/2024 03:15:20 UTC
Last modified on: 06/05/2024 20:38:26 UTC