# CVE-2025-0890: Hardcoded credentials in VMG4325-B10A firmware

> Attackers can log in to the management interface using insecure default Telnet credentials if administrators fail to change them.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Feb 2025
- **Updated:** 12 Feb 2025
- **Also known as:** GHSA-q2vf-jq2x-689c

## What is CVE-2025-0890?

CVE-2025-0890 is a critical vulnerability in Zyxel VMG4325-B10A firmware, published on 4 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-522 (Insufficiently Protected Credentials), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2025-0890?

It affects 14 products.


Products: Zyxel Sbg3300-N000 Firmware, Zyxel Sbg3300-Nb00 Firmware, Zyxel Sbg3500-N000 Firmware, Zyxel Sbg3500-Nb00 Firmware, Zyxel Vmg1312-B10a Firmware, Zyxel Vmg1312-B10b Firmware, Zyxel Vmg1312-B10e Firmware, Zyxel Vmg3312-B10a Firmware, Zyxel Vmg3313-B10a Firmware, Zyxel Vmg3926-B10b Firmware, Zyxel Vmg4325-B10a Firmware, Zyxel Vmg4380-B10a Firmware, Zyxel Vmg8324-B10a Firmware, Zyxel Vmg8924-B10a Firmware.

## How do I fix CVE-2025-0890?

No fix has been published for CVE-2025-0890 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-0890 being exploited?

There is no known exploitation of CVE-2025-0890 in the wild and no public exploit code.

Public exploit code:

- From a bare PCB to root: hardware-hacking a ZyXEL P-870HN (BCM6368) over UART — CVE-2025-0890 + CVE-2024-40891, on my own hardware. (github_poc): https://github.com/Danyw24/zyxel-p870hn-hardware-hacking

## Other vulnerabilities in Zyxel VMG4325-B10A firmware

- [CVE-2024-40890](https://insights.sbomify.com/CVE-2024-40890/): Zyxel DSL CPE OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2024-40891](https://insights.sbomify.com/CVE-2024-40891/): Zyxel DSL CPE OS Command Injection (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-0890 and fix it if it is affected.

What it is: CVE-2025-0890 is a critical vulnerability in Zyxel VMG4325-B10A firmware, published on 4 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-0890 in the wild and no public exploit code.

Affected product: Zyxel VMG4325-B10A firmware. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-0890/ (Markdown: https://insights.sbomify.com/CVE-2025-0890/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-0890
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-0890
- OSV: https://osv.dev/vulnerability/CVE-2025-0890

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-0890/
Summaries are generated and may contain mistakes; the official description above is the record.