# CVE-2021-45918: NHI’s health insurance web service component – Heap-based Buffer Overflow

> A remote attacker can cause a heap-based buffer overflow in the NHI health insurance web service, leading to a denial of service requiring a system restart.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Jun 2022
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-qhhp-8cc7-vf7w

## What is CVE-2021-45918?

CVE-2021-45918 is a high-severity memory corruption vulnerability in NHI health insurance web service component, published on 20 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

NHI’s health insurance web service component has insufficient validation for input string length, which can result in heap-based buffer overflow attack. A remote attacker can exploit this vulnerability to flood the memory space reserved for the program, in order to terminate service without authentication, which requires a system restart to recover service.

Weakness: CWE-1284 (Improper Validation of Specified Quantity in Input), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2021-45918?

It affects 1 product.


Products: Nhi Health Insurance Web Service Component.

## How do I fix CVE-2021-45918?

No fix has been published for CVE-2021-45918 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-45918 being exploited?

There is no known exploitation of CVE-2021-45918 in the wild and no public exploit code.

## Other vulnerabilities in NHI health insurance web service component

- [CVE-2022-35217](https://insights.sbomify.com/CVE-2022-35217/): NHI card’s web service component - Stack-based Buffer Overflow-1 (high 7.8)
- [CVE-2022-35218](https://insights.sbomify.com/CVE-2022-35218/): NHI card’s web service component - Heap-based Buffer Overflow (medium 5.5)
- [CVE-2022-35219](https://insights.sbomify.com/CVE-2022-35219/): NHI card’s web service component - Stack-based Buffer Overflow-2 (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-45918 and fix it if it is affected.

What it is: CVE-2021-45918 is a high-severity memory corruption vulnerability in NHI health insurance web service component, published on 20 Jun 2022. 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-2021-45918 in the wild and no public exploit code.

Affected product: NHI health insurance web service component. 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-2021-45918/ (Markdown: https://insights.sbomify.com/CVE-2021-45918/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-45918
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-45918
- OSV: https://osv.dev/vulnerability/CVE-2021-45918

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-45918/
Summaries are generated and may contain mistakes; the official description above is the record.