CVE-2019-15803

mediumpriority · track · 36EPSS 0.013 · 71 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.32% (71st) EPSS
CVSS 6.4 · medium
Is it mine?
19 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Through an undocumented sequence of keypresses, undocumented functionality is triggered. A diagnostics shell is triggered via CTRL-ALT-t, which prompts for the password returned by fds_sys_passDebugPasswd_ret(). The firmware contains access control checks that determine if remote users are allowed to access this functionality. The function that performs this check (fds_sys_remoteDebugEnable_ret in libfds.so) always return TRUE with no actual checks performed. The diagnostics menu allows for reading/writing arbitrary registers and various other configuration parameters which are believed to be related to the network interface chips.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.4–9.1

v2.06.4mediumAV:N/AC:L/Au:N/C:P/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 4.9
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 5.2
v3.19.1criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · FSTEC (BDU) RU
v3.18.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

03

affected products (19)

Products and version ranges known to be affected.

04

also known as (4)

Other names and identifiers for this entity.

05

sources

Which sources assert this record, and when.

published 2019-11-14modified 2026-06-17
07

references (7)

External citations — patches, advisories, analysis.

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