Tew 657Brm Firmware CVE-2026-5355

Q: What is the CVSS score of CVE-2026-5355?

CVE-2026-5355 has a CVSS 4.0 base score of 2.1 (Low). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.8%.

EUVD-2026-18412 LOW

Command Injection (CWE-77)

2026-04-02 cna@vuldb.com

GHSA-64fp-48cj-ffvx

Command Injection Tew 657Brm Firmware Trendnet

2.1

CVSS 4.0 · Vendor: vuldb

Severity by source

Vendor (vuldb) PRIMARY

2.1 LOW

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from Vendor (vuldb) · only source for this CVE.

CVSS VectorVendor: vuldb

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Severity Changed

Apr 29, 2026 - 01:11 NVD

MEDIUM LOW

CVSS changed

Apr 29, 2026 - 01:11 NVD

5.3 (MEDIUM) 2.1 (LOW)

EUVD ID Assigned

Apr 02, 2026 - 17:22 euvd

EUVD-2026-18412

Analysis Generated

Apr 02, 2026 - 17:22 vuln.today

CVE Published

Apr 02, 2026 - 17:16 nvd

MEDIUM 5.3

DescriptionCVE.org

A vulnerability has been found in Trendnet TEW-657BRM 1.00.1. Affected by this issue is the function vpn_drop of the file /setup.cgi. The manipulation of the argument policy_name leads to os command injection. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used. The vendor confirms, that "[t]he product in question (...) has been discontinued and end of life since June 23, 2011, that is more than 14 years ago. We no longer provide support for this product, so we are not able to confirm the vulnerabilities. We will make an announcement on our website's product support page and notify customers who registered their products with us." This vulnerability only affects products that are no longer supported by the maintainer.

AnalysisAI

Remote authenticated OS command injection in TrendNet TEW-657BRM 1.00.1 router via the vpn_drop function in /setup.cgi allows low-privileged attackers to execute arbitrary commands with limited impact on system confidentiality, integrity, and availability. The vendor confirmed the product reached end-of-life on June 23, 2011, and will not provide support or patches. Public exploit code exists, but this vulnerability affects only discontinued hardware no longer receiving vendor maintenance.

Technical ContextAI

The vulnerability exists in the vpn_drop function within /setup.cgi of the TrendNet TEW-657BRM wireless router firmware. The root cause is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command), indicating insufficient input validation or sanitization of the policy_name argument before it is passed to an OS command execution function. The attack surface involves the web-based management interface accessible remotely, with command injection occurring at the application layer before shell metacharacters are properly escaped or filtered.

RemediationAI

No vendor-released patch exists, as TrendNet confirmed the product is discontinued and will not receive further support or updates. Organizations operating TEW-657BRM units should immediately decommission the affected hardware and replace it with a modern, actively maintained router. If discontinuation is not immediately feasible, implement network-level controls: restrict administrative access to the /setup.cgi interface via firewall rules, disable remote management if not required, and ensure only trusted users have credentials to the device's web interface. Monitor for suspicious command execution patterns if the device must remain in service. Review the public exploit disclosed at https://github.com/panda666-888/vuls/blob/main/trendnet/tew-657brm/vpn_drop.md to understand the attack mechanism and ensure your access controls prevent exploitation.