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关联漏洞

描述

IOS audio buffer overflow CVE-2025-31200 POC

介绍

# CVE-2025-31200: CoreAudio APAC Channel Remapping Buffer Overflow

## Vulnerability Overview

CVE-2025-31200 is a buffer overflow vulnerability in Apple's CoreAudio framework affecting the Apple Positional Audio Codec (APAC) decoder. The bug exists in the `APACChannelRemapper::Process` function within `APACHOADecoder::DecodeAPACFrame`.

**Affected Systems:**
- iOS < 18.4.1
- macOS < 15.4.1
- All Apple devices with CoreAudio framework

## Technical Details

### Root Cause
The vulnerability stems from a logic error in channel layout validation:

1. The `mRemappingArray` is sized based on the lower 2 bytes of `mChannelLayoutTag` from the global channel layout
2. During audio frame processing, the decoder uses a separate remapping channel layout count to iterate through this array
3. By creating a mismatch between these two channel counts, an attacker can cause out-of-bounds memory access

### Attack Vector
The exploit works by crafting a malicious APAC audio file with:
- Global channel layout: 4 channels (controls array allocation size)
- Remapping channel layout: 64 channels (controls iteration count)
- Result: 16x out-of-bounds memory access during channel remapping

## Proof of Concept

This repository contains a Python implementation that generates the malicious APAC cookie exploiting this vulnerability.

### Files
- `poc.py` - Main exploit generator
- `generate_audio_simple.py` - Audio file generation
- `caf_utils.py` - APAC cookie manipulation utilities
- `parser.py` - Cookie parsing and exploit payload creation
- `test_exploit.py` - Exploit verification and analysis
- `create_malicious_mp4.py` - MP4 payload generation

### Usage
```bash
# Generate malicious APAC cookie
pip install numpy construct
python3 poc.py

# Verify exploit payload
python3 test_exploit.py

# Create malicious MP4 (requires macOS afconvert)
python3 create_malicious_mp4.py
```

The scripts generate:
- Benign test audio files (WAV, M4A, CAF)
- `exploit_cookie.dat` - Malicious APAC cookie with channel count mismatch
- `malicious_apac.m4a` - Weaponized MP4 file ready for testing

### Exploitation Process
1. Create channel layout mismatch in APAC cookie (`poc.py`)
2. Verify payload integrity (`test_exploit.py`)
3. Embed cookie in MP4/M4A audio container (`create_malicious_mp4.py`)
4. Deploy malicious file to vulnerable system
5. Trigger processing via audio playback (AVAudioPlayer, web browser, etc.)
6. Out-of-bounds access occurs in `APACChannelRemapper::Process`

### Testing Environment
To verify the exploit on vulnerable systems:
- **Target**: macOS < 15.4.1 or iOS < 18.4.1
- **Tools**: Xcode with Guard Malloc enabled
- **Expected crash**: `APACChannelRemapper::Process` with EXC_BAD_ACCESS
- **Debugging**: Use LLDB to examine memory corruption patterns

## Impact and Exploitation Potential

### Immediate Effects
- **Denial of Service**: Guaranteed crash when malicious audio is processed
- **Memory Corruption**: Out-of-bounds read/write operations
- **Application Termination**: Any app processing the malicious audio will crash

### Advanced Exploitation
With careful payload crafting, this vulnerability could potentially be leveraged for:

**Code Execution**: By controlling the out-of-bounds write operations, an attacker might:
- Overwrite function pointers or virtual table entries
- Corrupt heap metadata to achieve arbitrary write primitives
- Chain with other vulnerabilities for full system compromise

**Sandbox Escape**: Since CoreAudio runs in various security contexts:
- Browser exploitation via HTML5 audio elements
- Email client exploitation via audio attachments  
- System service exploitation in mediaserverd

**Remote Attack Scenarios**:
- Web-based attacks through malicious audio content
- Messaging app exploitation via audio message attachments
- Email-based attacks with malicious audio files
- Drive-by downloads of malicious media content

### Attack Vectors
- **Web browsers** processing HTML5 audio/video with APAC encoding
- **Media players** and streaming applications
- **Messaging applications** handling audio attachments
- **Email clients** processing multimedia content
- **System media services** automatically processing audio files

## Mitigation

Apple addressed this vulnerability in:
- iOS 18.4.1 (April 2025)
- macOS 15.4.1 (April 2025)

The fix validates channel counts between global and remapping layouts before processing, preventing the mismatch that causes the buffer overflow.

![Alt text](pewpew/pewpew.jpg)

## Disclaimer

This proof of concept is provided for educational and research purposes only. It demonstrates a critical security vulnerability in Apple's CoreAudio framework to help security researchers understand the attack mechanics and improve defensive measures.

文件快照

 [4.0K]  /data/pocs/458fb42973ec8435b64a9d213221f2fbd655cdbf
├── [1.1K]  caf_utils.py
├── [ 922]  create_malicious_mp4.py
├── [3.4K]  generate_audio.py
├── [1.4K]  parser.py
├── [4.0K]  pewpew
│   └── [ 63K]  pewpew.jpg
├── [1.2K]  poc.py
├── [4.6K]  README.md
└── [4.1K]  test_exploit.py

1 directory, 8 files

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