# CVE-2017-7964: Hardcoded credentials in n/a

> Remote attackers can exploit default TELNET credentials to gain root access and modify DNS settings, enabling hijacking attacks on Zyxel WRE6505 devices.

- **Severity:** Critical 10.0 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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:** 19 Apr 2017
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-2wc3-9w3j-8phw

## What is CVE-2017-7964?

CVE-2017-7964 is a critical vulnerability in n/a, published on 19 Apr 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Zyxel WRE6505 devices have a default TELNET password of 1234 for the root and admin accounts, which makes it easier for remote attackers to conduct DNS hijacking attacks by reconfiguring the built-in dnshijacker process.

Weakness: CWE-1188 (Initialization of a Resource with an Insecure Default)

## Which versions are affected by CVE-2017-7964?

It affects 1 product.


Products: Zyxel Wre6505 Firmware.

## How do I fix CVE-2017-7964?

No fix has been published for CVE-2017-7964 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-7964 being exploited?

There is no known exploitation of CVE-2017-7964 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-7256](https://insights.sbomify.com/CVE-2026-7256/): Command injection in WRE6505 v2 firmware (high 8.8)
- [CVE-2026-7255](https://insights.sbomify.com/CVE-2026-7255/): Auth bypass in WRE6505 v2 firmware (medium 6.5)
- [CVE-2026-6058](https://insights.sbomify.com/CVE-2026-6058/): Cross-site scripting in WRE6505 v2 firmware (medium 4.5)
- [CVE-2026-7257](https://insights.sbomify.com/CVE-2026-7257/): Information disclosure in WRE6505 v2 firmware (medium 4.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-7964 and fix it if it is affected.

What it is: CVE-2017-7964 is a critical vulnerability in n/a, published on 19 Apr 2017. 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-2017-7964 in the wild and no public exploit code.

Affected product: n/a. 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-2017-7964/ (Markdown: https://insights.sbomify.com/CVE-2017-7964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-7964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-7964
- OSV: https://osv.dev/vulnerability/CVE-2017-7964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-7964/
Summaries are generated and may contain mistakes; the official description above is the record.