# CVE-2025-9779: TOTOLINK A702R formFilter sub_4162DC buffer overflow

> Remote attackers can trigger a buffer overflow in the TOTOLINK A702R router's formFilter function, potentially leading to arbitrary code execution.

- **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 Sep 2025
- **Updated:** 2 Sep 2025
- **Also known as:** GHSA-ph9m-5932-3v52

## What is CVE-2025-9779?

CVE-2025-9779 is a high-severity memory corruption vulnerability in TOTOLINK A702R, published on 1 Sep 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was detected in TOTOLINK A702R 4.0.0-B20211108.1423. Affected by this vulnerability is the function sub_4162DC of the file /boafrm/formFilter. The manipulation of the argument ip6addr results in buffer overflow. It is possible to launch the attack remotely. The exploit is now 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-2025-9779?

It affects 1 product.


Products: Totolink A702r Firmware.

## How do I fix CVE-2025-9779?

No fix has been published for CVE-2025-9779 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-9779 being exploited?

There is no known exploitation of CVE-2025-9779 in the wild and no public exploit code.

## Other vulnerabilities in TOTOLINK A702R

- [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)
- [CVE-2025-8136](https://insights.sbomify.com/CVE-2025-8136/): TOTOLINK A702R HTTP POST Request formFilter buffer overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-9779 and fix it if it is affected.

What it is: CVE-2025-9779 is a high-severity memory corruption vulnerability in TOTOLINK A702R, published on 1 Sep 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-9779 in the wild and no public exploit code.

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-2025-9779/ (Markdown: https://insights.sbomify.com/CVE-2025-9779/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-9779
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-9779
- OSV: https://osv.dev/vulnerability/CVE-2025-9779

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-9779/
Summaries are generated and may contain mistakes; the official description above is the record.