# CVE-2021-3641: Improper Link Resolution Before File Access in Bitdefender GravityZone (VA-9921)

> A local attacker can cause a denial of service in Bitdefender Endpoint Security Tools via improper link resolution.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H`)
- **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:** 9 Nov 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-mg9g-xrgm-6mf3

## What is CVE-2021-3641?

CVE-2021-3641 is a medium-severity path traversal vulnerability in Bitdefender GravityZone, published on 9 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Link Resolution Before File Access ('Link Following') vulnerability in the EPAG component of Bitdefender Endpoint Security Tools for Windows allows a local attacker to cause a denial of service. This issue affects: Bitdefender GravityZone version 7.1.2.33 and prior versions.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2021-3641?

It affects 1 product.


Products: Bitdefender Gravityzone.

## How do I fix CVE-2021-3641?

No fix has been published for CVE-2021-3641 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3641 being exploited?

There is no known exploitation of CVE-2021-3641 in the wild and no public exploit code.

## Other vulnerabilities in Bitdefender GravityZone

- [CVE-2017-8931](https://insights.sbomify.com/CVE-2017-8931/): Privilege escalation in n/a (critical 9.8)
- [CVE-2018-8955](https://insights.sbomify.com/CVE-2018-8955/): Code injection in n/a (critical 9.8)
- [CVE-2025-2244](https://insights.sbomify.com/CVE-2025-2244/): Insecure PHP deserialization issue in GravityZone Console (VA-12634) (critical 9.5)
- [CVE-2024-6980](https://insights.sbomify.com/CVE-2024-6980/): Verbose error handling issue in GravityZone Update Server proxy service (critical 9.2)
- [CVE-2022-2830](https://insights.sbomify.com/CVE-2022-2830/): Deserialization of Untrusted Data in GravityZone Console On-Premise (VA-10573) (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3641 and fix it if it is affected.

What it is: CVE-2021-3641 is a medium-severity path traversal vulnerability in Bitdefender GravityZone, published on 9 Nov 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-2021-3641 in the wild and no public exploit code.

Affected product: Bitdefender GravityZone. 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-2021-3641/ (Markdown: https://insights.sbomify.com/CVE-2021-3641/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3641
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3641
- OSV: https://osv.dev/vulnerability/CVE-2021-3641

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3641/
Summaries are generated and may contain mistakes; the official description above is the record.