# CVE-2021-45036: Velneo vClient improper authentication

> An attacker with a victim's username and hashed password can spoof their identity to gain unauthorized access to the Velneo vClient server.

- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/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:** 28 Nov 2022
- **Updated:** 25 Apr 2025
- **Also known as:** GHSA-c83p-m9mw-q96q

## What is CVE-2021-45036?

CVE-2021-45036 is a high-severity authentication bypass vulnerability in Velneo vClient, published on 28 Nov 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Velneo vClient on its 28.1.3 version, could allow an attacker with knowledge of the victims's username and hashed password to spoof the victim's id against the server.

Weakness: CWE-287 (Improper Authentication), CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2021-45036?

It affects 1 product.


Products: Velneo Vclient.

## How do I fix CVE-2021-45036?

No fix has been published for CVE-2021-45036 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-45036 being exploited?

There is no known exploitation of CVE-2021-45036 in the wild and no public exploit code.

## Other vulnerabilities in Velneo vClient

- [CVE-2021-45035](https://insights.sbomify.com/CVE-2021-45035/): Velneo vClient Improper authentication (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-45036 and fix it if it is affected.

What it is: CVE-2021-45036 is a high-severity authentication bypass vulnerability in Velneo vClient, published on 28 Nov 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-2021-45036 in the wild and no public exploit code.

Affected product: Velneo vClient. 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-2021-45036/ (Markdown: https://insights.sbomify.com/CVE-2021-45036/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-45036
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-45036
- OSV: https://osv.dev/vulnerability/CVE-2021-45036

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-45036/
Summaries are generated and may contain mistakes; the official description above is the record.