CVE-2022-43237: Stack-buffer-overflow Vulnerability in Libde265 v1..8, Resulting in Denial of Service (DoS) Attacks

A critical vulnerability (CVE-2022-43237) has been discovered in the Libde265 library, version 1..8, which could lead to Denial of Service (DoS) attacks. The issue arises due to a stack-buffer-overflow vulnerability within the void put_epel_hv_fallback function found in the fallback-motion.cc file. Attackers may exploit this vulnerability by submitting a specifically crafted video file designed to trigger a memory overflow.

Details

The Libde265 library is an open-source software project providing a highly optimized implementation of the H.265/HEVC video codec, which has been widely adopted for storing and streaming high-quality video content. The vulnerability was discovered in version 1..8 of Libde265; thus, it is essential to update to a patched version as soon as possible to mitigate the risk.

Exploit

The bug is a stack-buffer-overflow vulnerability that arises within the void put_epel_hv_fallback function in the fallback-motion.cc file. An attacker can exploit this vulnerability by crafting and submitting a malicious video file that, when processed by the vulnerable Libde265 library, would lead to a memory overflow, causing a crash or, in some cases, potentially leading to the execution of arbitrary code.

Here's a code snippet illustrating the vulnerable function in fallback-motion.cc

template<class pixel_t> static void FUNC(put_epel_hv)(uint8_t *_dst, ptrdiff_t dststride,
                                                      const uint8_t *_src, ptrdiff_t srcstride,
                                                      int height, intptr_t mx, intptr_t my,
                                                      struct FUNC(hevcdsp_edge_derivative) *ed_data) {
  pixel_t *dst = (pixel_t *) _dst;
  const pixel_t *src = (const pixel_t *) _src;
  srcstride /= sizeof(pixel_t);
  dststride /= sizeof(pixel_t);

  src -= EPEL_EXTRA_BEFORE * srcstride;
  
  //...code continues
}

The above code snippet shows a part of the function where the buffer overflow occurs. The problem is that the function lacks proper input validation and checks, which allows an attacker to craft a malicious video file that eventually overflow the memory and leads to a crash or other unintended behavior.

Original References

1. The Libde265 library can be found at this GitHub repository: https://github.com/strukturag/libde265
2. The official vulnerability disclosure is documented at https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-43237

Mitigation

To protect yourself against this vulnerability, it is essential to update your Libde265 library to the latest patched version immediately. Keep an eye on the official repository for updates, and always follow best practices to prevent stack-buffer-overflow vulnerabilities in your codebase.

For developers working with Libde265, use proper input validation and error handling to impede the ability of attackers to craft malicious video files that might take advantage of this vulnerability. Additionally, consider implementing methods for verifying the integrity of video files before processing them to further secure your application.

Conclusion

CVE-2022-43237 is a critical vulnerability in Libde265 v1..8, which has the potential to lead to Denial of Service attacks and poses a significant risk to users and applications that rely on this library for video decoding. By updating to the latest patched version and following best practices, both users and developers can reduce the likelihood of falling victim to potential exploitation.

Timeline

Published on: 11/02/2022 14:15:00 UTC
Last modified on: 02/27/2023 15:18:00 UTC