# CVE-2025-4271: TOTOLINK A720R cstecgi.cgi information disclosure

> Remote attackers can disclose system logs via the cstecgi.cgi endpoint on TOTOLINK A720R routers, potentially exposing sensitive configuration data.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/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:** 5 May 2025
- **Updated:** 5 May 2025
- **Also known as:** GHSA-4xv4-mw36-x4rv

## What is CVE-2025-4271?

CVE-2025-4271 is a medium-severity vulnerability in TOTOLINK A720R, published on 5 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was found in TOTOLINK A720R 4.1.5cu.374. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument topicurl with the input showSyslog leads to information disclosure. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Weakness: CWE-284 (Improper Access Control), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2025-4271?

It affects 1 product.


Products: Totolink A720r Firmware.

## How do I fix CVE-2025-4271?

No fix has been published for CVE-2025-4271 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-4271 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-4271 exists.

## Other vulnerabilities in TOTOLINK A720R

- [CVE-2023-23064](https://insights.sbomify.com/CVE-2023-23064/): Missing authorization in n/a (critical 9.8)
- [CVE-2021-45740](https://insights.sbomify.com/CVE-2021-45740/): Denial of service in n/a (critical 9.8)
- [CVE-2021-45742](https://insights.sbomify.com/CVE-2021-45742/): Command injection in n/a (critical 9.8)
- [CVE-2021-35324](https://insights.sbomify.com/CVE-2021-35324/): Auth bypass in n/a (critical 9.8)
- [CVE-2021-35327](https://insights.sbomify.com/CVE-2021-35327/): Missing authorization in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4271 and fix it if it is affected.

What it is: CVE-2025-4271 is a medium-severity vulnerability in TOTOLINK A720R, published on 5 May 2025. 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-2025-4271 exists.

Affected product: TOTOLINK A720R. 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-2025-4271/ (Markdown: https://insights.sbomify.com/CVE-2025-4271/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4271
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4271
- OSV: https://osv.dev/vulnerability/CVE-2025-4271

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4271/
Summaries are generated and may contain mistakes; the official description above is the record.