# CVE-2018-25316: Tenda W308R v2 V5.07.48 Cookie Session Weakness DNS Change

> Unauthenticated attackers can bypass session validation to modify DNS settings on Tenda W308R routers, enabling traffic redirection.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Apr 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-65qg-r2jh-j3cm

## What is CVE-2018-25316?

CVE-2018-25316 is a critical authentication bypass vulnerability in Tenda W308R v2, published on 29 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Tenda W308R v2 V5.07.48 contains a cookie session weakness vulnerability that allows unauthenticated attackers to modify DNS settings by exploiting insufficient session validation. Attackers can send GET requests to the goform/AdvSetDns endpoint with a crafted admin language cookie to change DNS servers and redirect user traffic to malicious sites.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2018-25316?

It affects 1 product.


Products: Tenda W308r Firmware.

## How do I fix CVE-2018-25316?

No fix has been published for CVE-2018-25316 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-25316 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25316 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-25316 and fix it if it is affected.

What it is: CVE-2018-25316 is a critical authentication bypass vulnerability in Tenda W308R v2, published on 29 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25316 exists.

Affected product: Tenda W308R v2. 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-2018-25316/ (Markdown: https://insights.sbomify.com/CVE-2018-25316/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-25316
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-25316
- OSV: https://osv.dev/vulnerability/CVE-2018-25316

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-25316/
Summaries are generated and may contain mistakes; the official description above is the record.