# CVE-2021-29245: Weak cryptography in n/a

> Weak pseudo-random generation for legacy API keys allows attackers to predict keys and take over accounts.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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:** 5 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-6p4w-gcxh-hf6c

## What is CVE-2021-29245?

CVE-2021-29245 is a medium-severity vulnerability in n/a, published on 5 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

BTCPay Server through 1.0.7.0 uses a weak method Next to produce pseudo-random values to generate a legacy API key.

Weakness: CWE-338 (Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG))

## Which versions are affected by CVE-2021-29245?

It affects 1 product.


Products: Btcpayserver Btcpay Server.

## How do I fix CVE-2021-29245?

No fix has been published for CVE-2021-29245 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-29245 being exploited?

There is no known exploitation of CVE-2021-29245 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-32984](https://insights.sbomify.com/CVE-2022-32984/): Information disclosure in n/a (high 7.5)
- [CVE-2021-29249](https://insights.sbomify.com/CVE-2021-29249/): Information disclosure in n/a (high 7.5)
- [CVE-2021-29246](https://insights.sbomify.com/CVE-2021-29246/): Path traversal in n/a (medium 6.7)
- [CVE-2021-29251](https://insights.sbomify.com/CVE-2021-29251/): Missing authorization in n/a (medium 6.5)
- [CVE-2023-0879](https://insights.sbomify.com/CVE-2023-0879/): Cross-site Scripting (XSS) - Stored in btcpayserver/btcpayserver (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-29245 and fix it if it is affected.

What it is: CVE-2021-29245 is a medium-severity vulnerability in n/a, published on 5 May 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-2021-29245 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-2021-29245/ (Markdown: https://insights.sbomify.com/CVE-2021-29245/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29245
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29245
- OSV: https://osv.dev/vulnerability/CVE-2021-29245

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-29245/
Summaries are generated and may contain mistakes; the official description above is the record.