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CVE-2019-15803

Published: Nov 14, 2019Updated: Nov 21, 2024 Sources: CVE List NVD BDUCWE-287
NVD MITRE
9.1CVSSCRITICAL
EPSS Score
1.3%
Top 32.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-287

Affected Products

GS1900-8Zyxel Communications Corp.Networking Infrastructure
GS1900-8HPZyxel Communications Corp.Networking Infrastructure
GS1900-10HPZyxel Communications Corp.Networking Infrastructure
GS1900-16Zyxel Communications Corp.Networking Infrastructure
GS1900-24EZyxel Communications Corp.Networking Infrastructure
zyxel communications corp.commercialTWNetworking Infrastructure
and 14 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Initial Access
View detailed technique mapping

References

https://nvd.nist.gov/vuln/detail/CVE-2019-15803
nvd.nist.gov
https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml
zyxel.com
https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html
jasper.la
and 1 more references View all →

Timeline

Published
Nov 14, 2019
Last Updated
Nov 21, 2024

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