# CVE-2021-31642: Integer overflow in n/a

> An attacker can cause a denial of service on CHIYU Technology IoT devices by sending an oversized integer to the web portal, requiring a reboot to restore service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-6jfx-f65x-7qfx

## What is CVE-2021-31642?

CVE-2021-31642 is a medium-severity vulnerability in n/a, published on 1 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A denial of service condition exists after an integer overflow in several IoT devices from CHIYU Technology, including BIOSENSE, Webpass, and BF-630, BF-631, and SEMAC. The vulnerability can be explored by sending an unexpected integer (> 32 bits) on the page parameter that will crash the web portal and making it unavailable until a reboot of the device.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2021-31642?

It affects 11 products.


Products: Chiyu-Tech Bf-630 Firmware, Chiyu-Tech Bf-631 Firmware, Chiyu-Tech Biosense Firmware, Chiyu-Tech Semac D1 Firmware, Chiyu-Tech Semac D2 Firmware, Chiyu-Tech Semac D2 N300 Firmware, Chiyu-Tech Semac D4 Firmware, Chiyu-Tech Semac S1 Osdp Firmware, Chiyu-Tech Semac S2 Firmware, Chiyu-Tech Semac S3v3 Firmware, Chiyu-Tech Webpass Firmware.

## How do I fix CVE-2021-31642?

No fix has been published for CVE-2021-31642 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31642 being exploited?

There is no known exploitation of CVE-2021-31642 in the wild and no public exploit code.

Public exploit code:

- CHIYU IoT Devices - Denial of Service (DoS) (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2021-31643](https://insights.sbomify.com/CVE-2021-31643/): Cross-site scripting in n/a (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31642 and fix it if it is affected.

What it is: CVE-2021-31642 is a medium-severity vulnerability in n/a, published on 1 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-31642 in the wild and no public exploit code.

Affected product: n/a. 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-2021-31642/ (Markdown: https://insights.sbomify.com/CVE-2021-31642/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31642
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31642
- OSV: https://osv.dev/vulnerability/CVE-2021-31642

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31642/
Summaries are generated and may contain mistakes; the official description above is the record.