# CVE-2024-0202: Cryptlib: rsa key exchange ciphersuites in tls vulnerable to marvin attack

> Attackers can decrypt RSA ciphertexts or forge signatures via timing attacks if RSA key exchange ciphersuites are explicitly enabled in the cryptlib library.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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 Feb 2024
- **Updated:** 16 Mar 2026
- **Also known as:** GHSA-2wff-jj2f-98c4

## What is CVE-2024-0202?

CVE-2024-0202 is a medium-severity vulnerability in cryptlib:cryptlib, published on 5 Feb 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security vulnerability has been identified in the cryptlib cryptographic library when cryptlib is compiled with the support for RSA key exchange ciphersuites in TLS (by setting the USE_RSA_SUITES define), it will be vulnerable to the timing variant of the Bleichenbacher attack. An attacker that is able to perform a large number of connections to the server will be able to decrypt RSA ciphertexts or forge signatures using server's certificate. THIS CVE ID IS CURRENTLY DISPUTED - MAINTAINER NOTE: There are only two situations where it's enabled, one is for fuzz-testing to exercise code paths that wouldn't otherwise be available, the other is for static source code analysis with tools like Coverity and Prefast, again to open up code paths that otherwise wouldn't be available.  It can also be enabled manually in two specific test builds just to make sure the code still compiles OK, to avoid bit rot and verify that the fuzz-testing build will compile without errors.

Weakness: CWE-203 (Observable Discrepancy), CWE-208 (Observable Timing Discrepancy)

## Which versions are affected by CVE-2024-0202?

It affects 1 product.


Products: Cryptlib Cryptlib.

## How do I fix CVE-2024-0202?

No fix has been published for CVE-2024-0202 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-0202 being exploited?

There is no known exploitation of CVE-2024-0202 in the wild and no public exploit code.

## Other vulnerabilities in cryptlib:cryptlib

- [CVE-2018-12433](https://insights.sbomify.com/CVE-2018-12433/): Information disclosure in n/a (medium 4.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-0202 and fix it if it is affected.

What it is: CVE-2024-0202 is a medium-severity vulnerability in cryptlib:cryptlib, published on 5 Feb 2024. 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-2024-0202 in the wild and no public exploit code.

Affected product: cryptlib:cryptlib. 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-2024-0202/ (Markdown: https://insights.sbomify.com/CVE-2024-0202/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-0202
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-0202
- OSV: https://osv.dev/vulnerability/CVE-2024-0202

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-0202/
Summaries are generated and may contain mistakes; the official description above is the record.