{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31847","assignerOrgId":"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c","state":"PUBLISHED","assignerShortName":"TuranSec","dateReserved":"2026-03-09T18:20:23.399Z","datePublished":"2026-03-23T12:07:05.062Z","dateUpdated":"2026-03-26T10:52:50.115Z"},"containers":{"cna":{"providerMetadata":{"orgId":"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c","shortName":"TuranSec","dateUpdated":"2026-03-26T10:52:50.115Z"},"title":"Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-912","description":"CWE-912 Hidden Functionality","type":"CWE"}]}],"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."}]}],"affected":[{"vendor":"Nexxt Solutions","product":"Nebula 300+","versions":[{"status":"affected","version":"<= 12.01.01.37","lessThanOrEqual":"Nebula300+_v12.01.01.37","versionType":"custom"}],"defaultStatus":"unaffected"}],"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. This exposes a privileged diagnostic interface that is not intended for external access and can be used to interact with the underlying system.","supportingMedia":[{"type":"text/html","base64":false,"value":"Hidden functionality in the <code>/goform/setSysTools</code> 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 <code>telnetManageEn=true</code> and <code>telnetPwd</code>, an authenticated attacker can activate a Telnet service on port 23. This exposes a privileged diagnostic interface that is not intended for external access and can be used to interact with the underlying system."}]}],"references":[{"url":"https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6/","name":"Official product page"},{"url":"https://nexxt-connectivity-frontend.s3.amazonaws.com/media/docs/Nebula300+_v12.01.01.37.zip","name":"Firmware download"}],"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"}}],"credits":[{"lang":"en","value":"Angel Barre (call4pwn)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.1"}},"adp":[{"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"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-23T15:52:16.990Z"}}]}}