# CVE-2020-20950: Weak cryptography in n/a

> An attacker can decrypt RSA ciphertexts via a Bleichenbacher oracle attack on the Microchip Libraries for Applications, leading to remote information disclosure.

- **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:** 19 Jan 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-vw76-vm27-jx3r

## What is CVE-2020-20950?

CVE-2020-20950 is a medium-severity vulnerability in n/a, published on 19 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in Microchip Libraries for Applications 2018-11-26 All up to 2018-11-26. The vulnerability can allow one to use Bleichenbacher's oracle attack to decrypt an encrypted ciphertext by making successive queries to the server using the vulnerable library, resulting in remote information disclosure.

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2020-20950?

It affects 2 products.


Products: Ietf Public Key Cryptography Standards \#1, Microchip Microchip Libraries for Applications.

## How do I fix CVE-2020-20950?

No fix has been published for CVE-2020-20950 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-20950 being exploited?

There is no known exploitation of CVE-2020-20950 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-20949](https://insights.sbomify.com/CVE-2020-20949/): Weak cryptography in n/a (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-20950 and fix it if it is affected.

What it is: CVE-2020-20950 is a medium-severity vulnerability in n/a, published on 19 Jan 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-2020-20950 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-2020-20950/ (Markdown: https://insights.sbomify.com/CVE-2020-20950/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-20950
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-20950
- OSV: https://osv.dev/vulnerability/CVE-2020-20950

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-20950/
Summaries are generated and may contain mistakes; the official description above is the record.