An issue was discovered on V-SOL V1600D4L V1.01.49 and V1600D-MINI V1.01.48 OLT devices. During the process of updating the firmware, the update script starts a telnetd -l /bin/sh process that does not require authentication for TELNET access.
https://seclists.org/fulldisclosure/2020/Jul/14
Source: Mitre, NVD
Published: 2020-11-29
Updated: 2026-06-17
Base Score: 2.1
Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:P/A:N
Severity: Low
Base Score: 5.5
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Severity: Medium
EPSS: 0.00048