NetMan 204 contains a hard-coded backdoor account with the username and password 'eurek' that grants administrative access. A remote, unauthenticated attacker can authenticate through the cgi-bin/login.cgi endpoint (for example /cgi-bin/login.cgi?username=eurek&password=eurek, which due to lax parameter validation can be shortened to /cgi-bin/login.cgi?username=eurek%20eurek) to obtain administrator privileges, allowing them to alter device configuration, enable the telnet/SSH services, and reset local user credentials.
https://www.vulncheck.com/advisories/netman-204-hard-coded-backdoor-credentials
Published: 2026-06-05
Updated: 2026-06-05
Base Score: 10
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
Severity: Critical
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: Critical
EPSS: 0.00058