{"id":"CVE-2026-31847","state":"PUBLISHED","title":"Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+","description":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23.","publishedAt":"2026-03-23T12:07:05.062Z","updatedAt":"2026-08-10T11:43:39.725Z","severity":{"score":8.5,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"TuranSec"},"assigner":"TuranSec","products":["Nexxt Solutions Nebula 300+"],"affected":[{"vendor":"Nexxt Solutions","product":"Nebula 300+","defaultStatus":"unaffected","versions":[{"version":"<= 12.01.01.37","status":"affected","lessThanOrEqual":"Nebula300+_v12.01.01.37","versionType":"custom"}]}],"references":["https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6/","https://nexxt-connectivity-frontend.s3.amazonaws.com/media/docs/Nebula300+_v12.01.01.37.zip"],"weaknesses":["CWE-912"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31847.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31847","state":"PUBLISHED","datePublished":"2026-03-23T12:07:05.062Z","dateUpdated":"2026-08-10T11:43:39.725Z","assignerShortName":"TuranSec","assignerOrgId":"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c","dateReserved":"2026-03-09T18:20:23.399Z"},"containers":{"cna":{"title":"Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+","descriptions":[{"lang":"en","value":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23."}],"affected":[{"vendor":"Nexxt Solutions","product":"Nebula 300+","defaultStatus":"unaffected","versions":[{"version":"<= 12.01.01.37","status":"affected","lessThanOrEqual":"Nebula300+_v12.01.01.37","versionType":"custom"}]}],"references":[{"url":"https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6/","name":"Official product page","tags":["third-party-advisory"]},{"url":"https://nexxt-connectivity-frontend.s3.amazonaws.com/media/docs/Nebula300+_v12.01.01.37.zip","name":"Firmware download","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"ADJACENT","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":8.5,"vectorString":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-912","lang":"en","description":"CWE-912 Hidden Functionality","type":"CWE"}]}],"providerMetadata":{"shortName":"TuranSec","orgId":"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c","dateUpdated":"2026-08-10T11:43:39.725Z"},"impacts":[{"descriptions":[{"lang":"en","value":"An attacker who can invoke the affected functionality can enable a privileged Telnet service remotely, exposing a diagnostic management interface and enabling further compromise of the device."}]}],"credits":[{"lang":"en","value":"Angel Barre (call4pwn)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.1"},"datePublic":"2026-03-23T12:07:05.062Z"},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-23T15:16:37.215985Z","id":"CVE-2026-31847","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-23T15:52:16.990Z"}}]}}}