# CVE-2020-13131: Information disclosure in n/a

> A malicious PIV token can trigger a memory leak in libykpiv, exposing sensitive data like PINs and keys to the host application.

- **Severity:** Medium 4.3 (`CVSS:3.0/AC:L/AV:P/A:N/C:H/I:N/PR:N/S:U/UI:R`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Jul 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-13131, GHSA-rx8c-cr48-p2ff, UBUNTU-CVE-2020-13131

## What is CVE-2020-13131?

CVE-2020-13131 is a medium-severity vulnerability in n/a, published on 9 Jul 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

An issue was discovered in Yubico libykpiv before 2.1.0. lib/util.c in this library (which is included in yubico-piv-tool) does not properly check embedded length fields during device communication. A malicious PIV token can misreport the returned length fields during RSA key generation. This will cause stack memory to be copied into heap allocated memory that gets returned to the caller. The leaked memory could include PINs, passwords, key material, and other sensitive information depending on the integration. During further processing by the caller, this information could leak across trust boundaries. Note that RSA key generation is triggered by the host and cannot directly be triggered by the token.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2020-13131?

It affects 3 products.


Products: Yubico Libykpiv, Yubico Piv Tool Manager, Yubico Yubikey Smart Card Minidriver.

## How do I fix CVE-2020-13131?

Upgrade to a fixed version.

## Is CVE-2020-13131 being exploited?

There is no known exploitation of CVE-2020-13131 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-13132](https://insights.sbomify.com/CVE-2020-13132/): Use after free in n/a (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-13131 and fix it if it is affected.

What it is: CVE-2020-13131 is a medium-severity vulnerability in n/a, published on 9 Jul 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-13131 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-2020-13131/ (Markdown: https://insights.sbomify.com/CVE-2020-13131/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-13131
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-13131
- OSV: https://osv.dev/vulnerability/CVE-2020-13131

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-13131/
Summaries are generated and may contain mistakes; the official description above is the record.