CVE-2022-3669: A Deep Dive into Axiomatic Bento4 Vulnerability - Code Snippets, References, and Exploit Analysis

A vulnerability was recently discovered in Axiomatic Bento4, a popular C++ class library, and tools for parsing and processing MP4 files. The vulnerability, labeled CVE-2022-3669, has been classified as problematic and affects the function AP4_AvccAtom::Create of the component mp4edit. This security issue can lead to a memory leak, and attackers can potentially initiate the attack remotely. Although the exploit is already publicly accessible, we will be providing an in-depth breakdown of the vulnerability, including code snippets, links to original references, and an analysis of the exploit. The vulnerability has been assigned the identifier VDB-212009.

Code Snippet

Let's first examine the code responsible for the memory leak in the AP4_AvccAtom::Create function of the Bento4 library:

AP4_Result AP4_AvccAtom::Create(AP4_Size         size,
                                AP4_ByteStream&  stream,
                                AP4_AtomFactory& factory,
                                AP4_Atom*&       atom)
{
    ...
    if (size < AP4_FULL_ATOM_HEADER_SIZE+7) {
        return AP4_ERROR_INVALID_FORMAT; // <-- missing delete statement, causing memory leak
    }
    ...
    atom = new AP4_AvccAtom(size, stream);
    return AP4_SUCCESS;
}

In the snippet above, the function checks whether the size is too small and should throw an AP4_ERROR_INVALID_FORMAT error. However, before returning the error, the implementation overlooks properly deallocating the memory, thereby causing a memory leak.

Exploit Details

The memory leak vulnerability allows an attacker to remotely manipulate the AP4_AvccAtom::Create function. By carefully crafting a malicious MP4 file and encouraging users to access it, an attacker can exploit this vulnerability and cause a memory leak. In turn, this memory leak can potentially lead to other issues such as denial of service, unauthorized access to sensitive information, or other security risks.

It is essential to note that the vulnerability and exploit have been disclosed to the public, implying that the likelihood of finding the precise vulnerability in active use is relatively high.

Links to Original References

1. Bento4 GitHub Repository: https://github.com/axiomatic-systems/Bento4
2. CVE Details - CVE-2022-3669: https://www.cvedetails.com/cve/CVE-2022-3669/
3. Vulnerability Database - VDB-212009: http://www.vulnerability-db.com/?vulnerability=212009

Conclusion

CVE-2022-3669 is a problematic vulnerability in Axiomatic Bento4, affecting the memory allocation of the AP4_AvccAtom::Create function. This vulnerability can lead to memory leaks and can be exploited remotely, as specific exploit details are now publicly accessible. To mitigate the risk of this vulnerability, it is recommended to keep Bento4 and other related dependencies up to date and regularly review the library's usage within your software to ensure proper implementation and avoid potential security risks. It is equally crucial to understand the underlying issues with memory management and work towards implementing code that safely handles memory allocation to mitigate the chances of encountering similar vulnerabilities in the future.

Timeline

Published on: 10/26/2022 19:15:00 UTC
Last modified on: 10/28/2022 15:22:00 UTC