Undocumented Functionality in Zyxel GS1900 Devices Due to CLI Signal Flaw
CVE-2019-15804

7.5HIGH

Key Information:

Vendor
Zyxel
Status
Gs1900-8 Firmware
Vendor
CVE Published:
14 November 2019

Summary

A security concern has been identified in Zyxel GS1900 devices running firmware prior to 2.50(AAHH.0)C0, which allows unauthorized access to a hidden menu through a SIGQUIT signal sent to the Command Line Interface (CLI). This menu includes options for password recovery for specific users but is intended to be restricted. The access check for this menu is not effectively enforced, particularly when accessed via a serial console, raising significant risk for potential unauthorized operations and device manipulation.

References

https://jasper.la/exploring-zyxel-gs1900-firmware-with-gh...
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https://www.zyxel.com/support/gs1900-switch-vulnerabiliti...
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CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.