# CVE-2024-4420: Denial of Service in Tink-cc

> An attacker can crash applications using Tink-cc by providing malformed or deeply nested JSON inputs to the JsonKeysetReader.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/S:N/AU:Y/V:D/RE:L/U:Green`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 21 May 2024
- **Updated:** 1 Aug 2024
- **Also known as:** GHSA-xhph-75hg-j96m

## What is CVE-2024-4420?

CVE-2024-4420 is a medium-severity denial of service vulnerability in Google Tink, published on 21 May 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

There exists a Denial of service vulnerability in Tink-cc in versions prior to 2.1.3.   *  An adversary can crash binaries using the crypto::tink::JsonKeysetReader in tink-cc by providing an input that is not an encoded JSON object, but still a valid encoded JSON element, for example a number or an array. This will crash as Tink just assumes any valid JSON input will contain an object.

  *  An adversary can crash binaries using the crypto::tink::JsonKeysetReader in tink-cc by providing an input containing many nested JSON objects. This may result in a stack overflow.

We recommend upgrading to version 2.1.3 or above

Weakness: CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2024-4420?

It affects 1 product.


Products: Google Tink C\+\+.

## How do I fix CVE-2024-4420?

No fix has been published for CVE-2024-4420 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-4420 being exploited?

There is no known exploitation of CVE-2024-4420 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-4420 and fix it if it is affected.

What it is: CVE-2024-4420 is a medium-severity denial of service vulnerability in Google Tink, published on 21 May 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-4420 in the wild and no public exploit code.

Affected product: Google Tink. 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-2024-4420/ (Markdown: https://insights.sbomify.com/CVE-2024-4420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-4420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-4420
- OSV: https://osv.dev/vulnerability/CVE-2024-4420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-4420/
Summaries are generated and may contain mistakes; the official description above is the record.