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An authentication bypass vulnerability in the Universal Plug and Play (UPnP) framework of the Sercomm AOT-4221SR 4.6 Dual Band GPON ONU…

Affects Sercomm AOT-4221SR Dual Band GPON ONU firmware AOT4221SR_R4.6, where the UPnP service listens on port 5555 by default. The checked facts list no vendor rating and no fix.

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

—Not rated
Exploited
No known exploitation
Fix
No fix listed
Who is exposed
Not reported

Do first: Workaround: The checked facts contain no workaround or fix. The exposure they describe is the unauthenticated UPnP service on port 5555, reachable from the local network, so that is the part to watch until the vendor publishes guidance.

Published
Last modified
Published
Not listed in CISA KEV
5/100 · provisional
Unclear
None on Exploit-DB, Metasploit or GitHub

Summary

The UPnP framework on the Sercomm AOT-4221SR GPON ONU router is affected by an authentication bypass that lets unauthenticated attackers send arbitrary commands to exposed administrative, WAN, LAN, and firewall services. This could allow an attacker to change routing and DNS settings, remove firewall rules, and fully take over the device and the network it protects.

Read the original description

An authentication bypass vulnerability in the Universal Plug and Play (UPnP) framework of the Sercomm AOT-4221SR 4.6 Dual Band GPON ONU device allows an attackers to execute arbitrary SOAP requests via port 5555. This flaw exposes 15 administrative, WAN, LAN, and firewall services without requiring credentials, enabling attackers to modify core routing tables, alter DNS servers, remove firewall rules, and completely compromise the network.

What to do

  • Workaround: The checked facts contain no workaround or fix. The exposure they describe is the unauthenticated UPnP service on port 5555, reachable from the local network, so that is the part to watch until the vendor publishes guidance.

Timeline

  1. CVE published
  2. Record last updated
  3. First seen by cve.now

Evidence 2

  1. Repository
  2. Link

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

FAQ

Questions about CVE-2026-117082

What does this mean?

The UPnP service accepts SOAP requests over HTTP without authentication, so any device on the local network can send them. The advisory describes complete loss of confidentiality, integrity and availability, including compromise of the LAN and WAN.Source: github.com

Am I affected, and how do I check?

Firmware AOT4221SR_R4.6 on the Sercomm AOT-4221SR Dual Band GPON ONU, where the UPnP service listens on port 5555 in its default configuration. Compare the device's firmware version with AOT4221SR_R4.6 and check whether the UPnP service is running.Source: github.com

What should I do about it?

The checked facts do not name a fixed firmware version, so no upgrade target is given. Check the vendor's advisory for an updated firmware release.Source: github.com

Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data

What if there's no patch?

The checked facts contain no workaround or fix. The exposure they describe is the unauthenticated UPnP service on port 5555, reachable from the local network, so that is the part to watch until the vendor publishes guidance.Source: github.com