# CVE-2021-32742: Untrusted data fed into `Data.init(base32Encoded:)` can result in exposing server memory and/or crash

> Attackers can crash the server or expose memory by feeding untrusted data to the base32 decoding function in the Vapor Swift framework.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jul 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-pqwh-c2f3-vxmq

## What is CVE-2021-32742?

CVE-2021-32742 is a high-severity denial of service vulnerability in vapor, published on 9 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Vapor is a web framework for Swift. In versions 4.47.1 and prior, bug in the `Data.init(base32Encoded:)` function opens up the potential for exposing server memory and/or crashing the server (Denial of Service) for applications where untrusted data can end up in said function. Vapor does not currently use this function itself so this only impact applications that use the impacted function directly or through other dependencies. The vulnerability is patched in version 4.47.2. As a workaround, one may use an alternative to Vapor's built-in `Data.init(base32Encoded:)`.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2021-32742?

2 open source packages ship an affected version, including github.com/vapor/vapor. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/vapor/vapor` | SwiftURL | All versions | 4.47.2 |
| `github.com/vapor/vapor` | SwiftURL | All versions | 4.47.2 |

Products: Vapor Project Vapor.

## How do I fix CVE-2021-32742?

Upgrade github.com/vapor/vapor to 4.47.2 or later.

## Is CVE-2021-32742 being exploited?

There is no known exploitation of CVE-2021-32742 in the wild and no public exploit code.

## Other vulnerabilities in vapor

- [CVE-2020-15230](https://insights.sbomify.com/CVE-2020-15230/): Arbitrary file read un Vapor (high 8.5)
- [CVE-2021-21328](https://insights.sbomify.com/CVE-2021-21328/): Denial of Service (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-32742 and fix it if it is affected.

What it is: CVE-2021-32742 is a high-severity denial of service vulnerability in vapor, published on 9 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-32742 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/vapor/vapor (SwiftURL): affected all versions; fixed in 4.47.2
- github.com/vapor/vapor (SwiftURL): affected all versions; fixed in 4.47.2

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-2021-32742/ (Markdown: https://insights.sbomify.com/CVE-2021-32742/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-32742
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-32742
- OSV: https://osv.dev/vulnerability/CVE-2021-32742

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-32742/
Summaries are generated and may contain mistakes; the official description above is the record.