CVE-2022-47069: Security Advisory and Exploit Information for p7zip 16.02 Heap-Buffer-Overflow Vulnerability

A newly discovered security vulnerability has been making waves in the software ecosystem, affecting the popular compression utility p7zip. This vulnerability, designated as CVE-2022-47069, has been identified as a heap-buffer-overflow vulnerability in p7zip 16.02, which may result in severe consequences if exploited. In this long read, you will find crucial information and details concerning the vulnerability, including code snippets, exploitation details, and links to original references.

Identification Details

CVE-2022-47069 refers to a heap-buffer-overflow vulnerability in p7zip 16.02. It specifically affects the function NArchive::NZip::CInArchive::FindCd(bool) at CPP/7zip/Archive/Zip/ZipIn.cpp, presenting various security implications. Heap-buffer-overflow vulnerabilities often occur when a program writes more data to a buffer that resides on the heap than its allocated size can hold, ultimately corrupting memory and possibly leading to malicious code execution.

The vulnerable code section in NArchive::NZip::CInArchive::FindCd(bool) can be seen below

// CPP/7zip/Archive/Zip/ZipIn.cpp
HRESULT CInArchive::FindCd(bool &found)
{
  // ...

  UInt64 testPos = curPos - cdSize64 - numEntries64;
  RINOK(inStream->Seek(testPos, STREAM_SEEK_SET, NULL));
  RINOK(ReadStream_ANY(inStream, &buf[], kBufferSize));

  // ...
}

As shown in the snippet, an attacker might exploit this vulnerability by crafting a malicious ZIP file containing an inflated value for cdSize64 and numEntries64. These values, when combined, could result in a buffer overflow, leading to potential arbitrary code execution.

Exploit Details

Exploiting this vulnerability would require an attacker to craft a malicious ZIP file, which, when processed by an affected version of p7zip, could trigger the heap-buffer-overflow and potentially allow for arbitrary code execution.

The exploitation steps are as follows

1. Create a malicious ZIP file with carefully crafted values for cdSize64 and numEntries64 in the Central Directory (CD) header.

3. When a user, service, or application attempts to process the ZIP file using p7zip 16.02, the crafted values trigger the heap-buffer-overflow caused by the use of an insufficient buffer in the NArchive::NZip::CInArchive::FindCd(bool) function.
4. The attacker could leverage this vulnerability to execute arbitrary code, escalate privileges, or compromise the target system.

Original References

The vulnerability was discovered and responsibly disclosed by security researchers. You can find more information about CVE-2022-47069 and the associated technical analysis in these original references:

- CVE: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-47069
- National Vulnerability Database (NVD): https://nvd.nist.gov/vuln/detail/CVE-2022-47069

Conclusion

It is crucial to stay informed and updated about vulnerabilities affecting your software. In this particular case, users and organizations utilizing p7zip 16.02 should apply any available patches or upgrades to mitigate the risks and potential consequences associated with CVE-2022-47069. Stay vigilant, and ensure your software solutions are up-to-date to minimize security risks.

Timeline

Published on: 08/22/2023 19:16:00 UTC
Last modified on: 08/26/2023 02:16:00 UTC