What is CVE-2020-29379?

CVE-2020-29379 is a medium-severity vulnerability in Vsolcn V1600d4l, classified under Missing Authentication for Critical Function. CVSS score: 5.5/10. Published 2020-11-29.

How severe is CVE-2020-29379?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Auth bypass in Vsolcn V1600d4l

CVE-2020-29379

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.

Vulnerability class: Broken Authentication

Published 2020-11-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Vsolcn V1600d4l
Vsolcn V1600d4l Firmware — versions 1.01.49
Vsolcn V1600d-Mini
Vsolcn V1600d-Mini Firmware — versions 1.01.48

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

seclists.org/fulldisclosure/2020/Jul/14 (Exploit, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2020-29379?: CVE-2020-29379 is a medium-severity vulnerability in Vsolcn V1600d4l, classified under Missing Authentication for Critical Function. CVSS score: 5.5/10. Published 2020-11-29.
How severe is CVE-2020-29379?: Medium severity. CVSS v3 base score is 5.5 out of 10.