# CVE-2025-6940: TOTOLINK A702R HTTP POST Request formParentControl buffer overflow

> Remote attackers can trigger a buffer overflow in the TOTOLINK A702R router's HTTP handler, potentially leading to code execution or privilege escalation.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Jul 2025
- **Updated:** 1 Jul 2025
- **Also known as:** GHSA-53q3-762m-2wvx

## What is CVE-2025-6940?

CVE-2025-6940 is a high-severity memory corruption vulnerability in TOTOLINK A702R, published on 1 Jul 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability classified as critical was found in TOTOLINK A702R 4.0.0-B20230721.1521. Affected by this vulnerability is an unknown functionality of the file /boafrm/formParentControl of the component HTTP POST Request Handler. The manipulation of the argument submit-url leads to buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-6940?

It affects 1 product.


Products: Totolink A702r Firmware.

## How do I fix CVE-2025-6940?

No fix has been published for CVE-2025-6940 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-6940 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-6940 exists.

## Other vulnerabilities in TOTOLINK A702R

- [CVE-2025-9779](https://insights.sbomify.com/CVE-2025-9779/): TOTOLINK A702R formFilter sub_4162DC buffer overflow (high 8.7)
- [CVE-2025-9780](https://insights.sbomify.com/CVE-2025-9780/): TOTOLINK A702R formIpQoS sub_419BE0 buffer overflow (high 8.7)
- [CVE-2025-9781](https://insights.sbomify.com/CVE-2025-9781/): TOTOLINK A702R formFilter sub_4162DC buffer overflow (high 8.7)
- [CVE-2025-9782](https://insights.sbomify.com/CVE-2025-9782/): TOTOLINK A702R formOneKeyAccessButton sub_4466F8 buffer overflow (high 8.7)
- [CVE-2025-9783](https://insights.sbomify.com/CVE-2025-9783/): TOTOLINK A702R formParentControl sub_418030 buffer overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-6940 and fix it if it is affected.

What it is: CVE-2025-6940 is a high-severity memory corruption vulnerability in TOTOLINK A702R, published on 1 Jul 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-6940 exists.

Affected product: TOTOLINK A702R. 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-2025-6940/ (Markdown: https://insights.sbomify.com/CVE-2025-6940/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-6940
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-6940
- OSV: https://osv.dev/vulnerability/CVE-2025-6940

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-6940/
Summaries are generated and may contain mistakes; the official description above is the record.