# CVE-2020-28918: Information disclosure in n/a

> Attackers can enumerate valid usernames via distinct error messages on the DualShield login form, facilitating targeted attacks.

- **Severity:** Medium 5.3 (`CVSS:3.1/AC:L/AV:N/A:N/C:L/I:N/PR:N/S:U/UI:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Feb 2021
- **Updated:** 30 May 2025
- **Also known as:** GHSA-gw6r-2xfv-2c8w

## What is CVE-2020-28918?

CVE-2020-28918 is a medium-severity vulnerability in n/a, published on 16 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

DualShield 5.9.8.0821 allows username enumeration on its login form. A valid username results in prompting for the password, whereas an invalid one will produce an "unknown username" error message.

## Which versions are affected by CVE-2020-28918?

It affects 1 product.


Products: Deepnetsecurity Dualshield.

## How do I fix CVE-2020-28918?

No fix has been published for CVE-2020-28918 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-28918 being exploited?

There is no known exploitation of CVE-2020-28918 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-28918 and fix it if it is affected.

What it is: CVE-2020-28918 is a medium-severity vulnerability in n/a, published on 16 Feb 2021. 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-2020-28918 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-2020-28918/ (Markdown: https://insights.sbomify.com/CVE-2020-28918/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-28918
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-28918
- OSV: https://osv.dev/vulnerability/CVE-2020-28918

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-28918/
Summaries are generated and may contain mistakes; the official description above is the record.