# CVE-2021-28496: Information disclosure in Arista EOS

> Authenticated users can leak BFD shared secret passwords via eAPI or JSON outputs in Arista EOS when shared secret profiles are configured.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 21 Oct 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-v5xw-5jg8-4q3j

## What is CVE-2021-28496?

CVE-2021-28496 is a medium-severity vulnerability in Arista EOS, published on 21 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

On systems running Arista EOS and CloudEOS with the affected release version, when using shared secret profiles the password configured for use by BiDirectional Forwarding Detection (BFD) will be leaked when displaying output over eAPI or other JSON outputs to other authenticated users on the device. The affected EOS Versions are: all releases in 4.22.x train, 4.23.9 and below releases in the 4.23.x train, 4.24.7 and below releases in the 4.24.x train, 4.25.4 and below releases in the 4.25.x train, 4.26.1 and below releases in the 4.26.x train

Weakness: CWE-522 (Insufficiently Protected Credentials), CWE-311 (Missing Encryption of Sensitive Data)

## Which versions are affected by CVE-2021-28496?

It affects 1 product.


Products: Arista Eos.

## How do I fix CVE-2021-28496?

No fix has been published for CVE-2021-28496 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-28496 being exploited?

There is no known exploitation of CVE-2021-28496 in the wild and no public exploit code.

## Other vulnerabilities in Arista EOS

- [CVE-2026-7473](https://insights.sbomify.com/CVE-2026-7473/): Arista Extensible Operating System Incomplete Comparison with Missing Factors (medium 6.9, exploited in the wild)
- [CVE-2015-8236](https://insights.sbomify.com/CVE-2015-8236/): Privilege escalation in n/a (critical 10.0)
- [CVE-2020-10188](https://insights.sbomify.com/CVE-2020-10188/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-18017](https://insights.sbomify.com/CVE-2017-18017/): Use after free in n/a (critical 9.8)
- [CVE-2017-14491](https://insights.sbomify.com/CVE-2017-14491/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28496 and fix it if it is affected.

What it is: CVE-2021-28496 is a medium-severity vulnerability in Arista EOS, published on 21 Oct 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-2021-28496 in the wild and no public exploit code.

Affected product: Arista EOS. 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-2021-28496/ (Markdown: https://insights.sbomify.com/CVE-2021-28496/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28496
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28496
- OSV: https://osv.dev/vulnerability/CVE-2021-28496

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28496/
Summaries are generated and may contain mistakes; the official description above is the record.