Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+
Priority LOW 39CWE-912Published · Updated
Key facts
- Attack vector
- Adjacent network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00445 38th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Nexxt Solutions | Nebula 300+ | <= 12.01.01.37 – Nebula300+_v12.01.01.37 | — | No fix listed | CNA |
- Nebula 300+ VendorNexxt Solutions Affected <= 12.01.01.37 – Nebula300+_v12.01.01.37 Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:nexxtsolutions:nebula300plus_firmware:*:*:*:*:*:*:*:* | up to 12.01.01.37 | Vulnerable | Nexxt Solutions |
| cpe:2.3:h:nexxtsolutions:nebula300plus:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Nexxt Solutions |
- cpe:2.3:o:nexxtsolutions:nebula300plus_firmware:*:*:*:*:*:*:*:* Versions up to 12.01.01.37 Vulnerable ·Nexxt Solutions
- cpe:2.3:h:nexxtsolutions:nebula300plus:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Nexxt Solutions
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-31847
- 2026-10-03 Alias added: GHSA-892q-6j8f-3q9c
- 2026-10-25 EPSS moved to the below the 50th percentile
- 2026-10-25 Priority changed: MEDIUM → LOW
References
Advisory 2
More Nexxt Solutions Nebula300plus Firmware vulnerabilities
- TI-2026-24401 Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+ CVSS 4.0HIGH 8.7
- TI-2026-24404 Nexxt Nebula 300+ - Lack of Rate Limiting Enables Brute-Force Attacks CVSS 4.0HIGH 7.7
- TI-2026-24402 Missing CSRF Protection on Administrative Endpoints in Nexxt Nebula 300+ CVSS 4.0HIGH 7.2
- TI-2026-24403 Plaintext Storage of Credentials in Configuration Backup in Nexxt Nebula 300+ CVSS 4.0MEDIUM 6.8
Sources
- CVE-2026-31847 · CVE Program
- CVE-2026-31847 · NVD
- FIRST EPSS
- GHSA-892q-6j8f-3q9c · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences