CVE-2022-43171 - Heap Buffer Overflow Vulnerability in LIEF v.12.1: Exploit Details, POC, and Mitigations

A newly discovered vulnerability, titled CVE-2022-43171, highlights a heap buffer overflow in the LIEF::MachO::BinaryParser::parse_dyldinfo_generic_bind function of LIEF v.12.1. Successful exploitation would enable attackers to cause a Denial of Service (DoS) by crafting a malicious MachO file. In this long read post, we will discuss the technical aspects of this exploit, including code snippets, links to original references, and remediation suggestions.

Vulnerability Details

LIEF (Library to Instrument Executable Formats) is an open-source project designed to parse and modify executable file formats, such as ELF, PE, and MachO. LIEF v.12.1, which is impacted by the CVE-2022-43171 vulnerability, contains a heap buffer overflow within the LIEF::MachO::BinaryParser::parse_dyldinfo_generic_bind function. The vulnerable code snippet is as follows:

void BinaryParser::parse_dyldinfo_generic_bind(void) {

  // ...

  const uint8_t* p          = this->stream_.read_array<uint8_t>(address, count);
  const uint8_t* end        = p + count;

  // ...

  for (const uint8_t* start = p; p != end; ) {

    // ...

    int64_t library_ordinal         = ;
    uint64_t uleb                   = ;
    int64_t sleb                    = ;

    // ...

    }
  }
}

As evident in the code snippet, an attacker can trigger the heap buffer overflow vulnerability by creating a modified MachO file, which can then lead to a Denial of Service (DoS) condition when parsed by the LIEF library.

Proof of Concept (POC)

Andre - a security researcher - disclosed this vulnerability to the LIEF developers. For the complete vulnerability disclosure, please visit the GitHub security advisory CVE-2022-43171. The advisory also provides a proof-of-concept MachO file that demonstrates the vulnerability.

Mitigation Recommendations

Until the vulnerability is officially patched in a later version of the LIEF library, organizations should consider the following mitigation strategies as temporary solutions:

1. Refrain from parsing untrusted, third-party MachO files without proper validation and file integrity checking.
2. Monitor applications and software for unusual activity, crash reports, or suspicious events that may indicate an attempted exploit or buffer overflow.

Additionally, when the LIEF project releases a new version that addresses this vulnerability, organizations and developers should immediately update to the latest patched version.

Conclusion

In summary, this long read post highlighted the heap buffer overflow vulnerability - CVE-2022-43171 - in the LIEF v.12.1 library's LIEF::MachO::BinaryParser::parse_dyldinfo_generic_bind function. By crafting a malicious MachO file, an attacker can potentially induce a Denial of Service (DoS) situation. To safeguard against such exploits, we recommend monitoring applications for unusual activities, validating file inputs, and staying up-to-date with security patches and updates.

Timeline

Published on: 11/17/2022 23:15:00 UTC
Last modified on: 11/21/2022 20:33:00 UTC