# CVE-2021-36724: ForeScout - SecureConnector Local Service DoS

> A local low-privileged user can crash the SecureConnector service by writing excessive characters to the installation path, causing a buffer overflow.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Dec 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-cvrj-cr4m-fg2f

## What is CVE-2021-36724?

CVE-2021-36724 is a medium-severity memory corruption vulnerability in ForeScout eServices / eNvoice, published on 29 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

ForeScout - SecureConnector Local Service DoS - A low privilaged user which doesn't have permissions to shutdown the secure connector service writes a large amount of characters in the installationPath. This will cause the buffer to overflow and override the stack cookie causing the service to crash.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2021-36724?

It affects 1 product.


Products: Forescout Secureconnector.

## How do I fix CVE-2021-36724?

No fix has been published for CVE-2021-36724 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-36724 being exploited?

There is no known exploitation of CVE-2021-36724 in the wild and no public exploit code.

## Other vulnerabilities in ForeScout eServices / eNvoice

- [CVE-2025-4660](https://insights.sbomify.com/CVE-2025-4660/): Remote Code Execution in Windows Secure Connector/ HPS Inspection Engine via Insecure Named Pipe Access (high 8.7)
- [CVE-2024-9950](https://insights.sbomify.com/CVE-2024-9950/): Abuse of Unauthenticated Compliance Recheck in SecureConnector (high 8.5)
- [CVE-2023-39374](https://insights.sbomify.com/CVE-2023-39374/): ForeScout NAC SecureConnector – CWE-427: Uncontrolled Search Path Element (high 7.8)
- [CVE-2016-9485](https://insights.sbomify.com/CVE-2016-9485/): Privilege escalation in Windows SecureConnector agent (high 7.8)
- [CVE-2016-9486](https://insights.sbomify.com/CVE-2016-9486/): Privilege escalation in Windows SecureConnector agent (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-36724 and fix it if it is affected.

What it is: CVE-2021-36724 is a medium-severity memory corruption vulnerability in ForeScout eServices / eNvoice, published on 29 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-36724 in the wild and no public exploit code.

Affected product: ForeScout eServices / eNvoice. 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-2021-36724/ (Markdown: https://insights.sbomify.com/CVE-2021-36724/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-36724
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-36724
- OSV: https://osv.dev/vulnerability/CVE-2021-36724

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-36724/
Summaries are generated and may contain mistakes; the official description above is the record.