WAVLINK WN553X1-B: OS command injection in OpenVPN file handler
Summary
The OpenVPN client file handler (function sub_4162A8 in /bin/ioos) of the WAVLINK WN553X1-B router firmware 260403_2.0.0 does not sanitize the file_id parameter. An authenticated attacker can inject operating system commands that run as root, which allows full compromise of the device. A public proof of concept exists. The factory-default password admin reportedly makes the required login trivial on devices where it was never changed.
Affected
- WAVLINK WN553X1-B, firmware 260403_2.0.0
- Other firmware versions: Unknown.
Fixed in
Unknown. No vendor fix or advisory found.
Workaround
- Remove remote administration and WAN access to the router's web interface.
- Change the default admin password.
- Restrict management access to a trusted management VLAN or specific IP addresses.
- No official mitigation from the vendor is known.
Exploitation
- Public proof of concept: yes (researcher write-up on GitHub).
- Authentication: a valid session is required; the default password admin may be used.
- In the wild: no confirmed exploitation found.
- CISA KEV: not checked.
Our recommendation
- Identify all WAVLINK WN553X1-B devices in use and check their firmware version.
- Remove internet exposure of the management interface and change the default password immediately.
- Isolate the devices from untrusted networks until a vendor fix is available.
- Check the device configuration for unexpected OpenVPN entries and monitor for firmware updates from WAVLINK.
- Verify the CVSS score once the NVD analysis is published, as sources currently disagree.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- VulDB vulnerability CVE-2026-120238 vuldb.com
- VulDB CVE page CVE-2026-120238 vuldb.com
- Researcher write-up: ovpn_file command injection (GitHub) github.com
- OffSeq Radar: CVE-2026-120238 radar.offseq.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 19:20.
Original description (NVD)
A vulnerability has been found in WAVLINK WN553X1-B 260403_2.0.0. This affects the function sub_4162A8 of the file /bin/ioos of the component ovpn_file Handler. Such manipulation of the argument file_id leads to os command injection. The attack can be executed remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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