# CVE-2016-7816: Weak cryptography in kintone mobile for Android

> Man-in-the-middle attackers can spoof servers and obtain sensitive information due to lack of X.509 certificate verification in the mobile app.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jun 2017
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-48r2-fhp3-vhcc

## What is CVE-2016-7816?

CVE-2016-7816 is a medium-severity vulnerability in Cybozu, Inc. kintone mobile for Android, published on 9 Jun 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Cybozu kintone mobile for Android 1.0.6 and earlier does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2016-7816?

It affects 1 product.


Products: Cybozu Kintone.

## How do I fix CVE-2016-7816?

No fix has been published for CVE-2016-7816 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-7816 being exploited?

There is no known exploitation of CVE-2016-7816 in the wild and no public exploit code.

## Other vulnerabilities in Cybozu, Inc. kintone mobile for Android

- [CVE-2016-1186](https://insights.sbomify.com/CVE-2016-1186/): Security feature bypass in n/a (medium 5.9)
- [CVE-2020-5573](https://insights.sbomify.com/CVE-2020-5573/): Information disclosure in Android App 'kintone mobile for Android' (medium 4.6)
- [CVE-2016-1185](https://insights.sbomify.com/CVE-2016-1185/): Information disclosure in n/a (low 2.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-7816 and fix it if it is affected.

What it is: CVE-2016-7816 is a medium-severity vulnerability in Cybozu, Inc. kintone mobile for Android, published on 9 Jun 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-2016-7816 in the wild and no public exploit code.

Affected product: Cybozu, Inc. kintone mobile for Android. 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-2016-7816/ (Markdown: https://insights.sbomify.com/CVE-2016-7816/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-7816
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-7816
- OSV: https://osv.dev/vulnerability/CVE-2016-7816

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-7816/
Summaries are generated and may contain mistakes; the official description above is the record.