# CVE-2021-41615: Weak cryptography in n/a

> Hardcoded nonce entropy in GoAhead WebServer allows attackers to bypass HTTP Digest Authentication security mechanisms.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Aug 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-m7x8-4574-hxw6

## What is CVE-2021-41615?

CVE-2021-41615 is a critical vulnerability in n/a, published on 8 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

websda.c in GoAhead WebServer 2.1.8 has insufficient nonce entropy because the nonce calculation relies on the hardcoded onceuponatimeinparadise value, which does not follow the secret-data guideline for HTTP Digest Access Authentication in RFC 7616 section 3.3 (or RFC 2617 section 3.2.1). NOTE: 2.1.8 is a version from 2003; however, the affected websda.c code appears in multiple derivative works that may be used in 2021. Recent GoAhead software is unaffected.

Weakness: CWE-331 (Insufficient Entropy)

## Which versions are affected by CVE-2021-41615?

It affects 1 product.


Products: Embedthis Goahead.

## How do I fix CVE-2021-41615?

No fix has been published for CVE-2021-41615 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41615 being exploited?

There is no known exploitation of CVE-2021-41615 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2017-17562](https://insights.sbomify.com/CVE-2017-17562/): Embedthis GoAhead Remote Code Execution (high 8.1, exploited in the wild)
- [CVE-2021-43298](https://insights.sbomify.com/CVE-2021-43298/): Security feature bypass in goahead (critical 9.8)
- [CVE-2021-42342](https://insights.sbomify.com/CVE-2021-42342/): File upload in n/a (critical 9.8)
- [CVE-2019-5096](https://insights.sbomify.com/CVE-2019-5096/): Use after free in EmbedThis (critical 9.8)
- [CVE-2017-1000471](https://insights.sbomify.com/CVE-2017-1000471/): Null dereference in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41615 and fix it if it is affected.

What it is: CVE-2021-41615 is a critical vulnerability in n/a, published on 8 Aug 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-2021-41615 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-2021-41615/ (Markdown: https://insights.sbomify.com/CVE-2021-41615/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41615
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41615
- OSV: https://osv.dev/vulnerability/CVE-2021-41615

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41615/
Summaries are generated and may contain mistakes; the official description above is the record.