# CVE-2023-40660: Opensc: potential pin bypass when card tracks its own login state

> Attackers can bypass PIN authentication on smart cards by passing an empty PIN, allowing unauthorized cryptographic operations and system access.

- **Severity:** Medium 6.6 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **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:** 6 Nov 2023
- **Updated:** 6 Nov 2025
- **Also known as:** AZL-31787, AZL-35074, CLSA-2026-1779368985, DEBIAN-CVE-2023-40660, GHSA-7635-x5f9-5458, OESA-2023-1766, OESA-2023-1767, UBUNTU-CVE-2023-40660

## What is CVE-2023-40660?

CVE-2023-40660 is a medium-severity authentication bypass vulnerability in Opensc Project Opensc, published on 6 Nov 2023. 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

A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logon/screen unlock and for small, permanently connected tokens to computers. Additionally, the token can internally track login status. This flaw allows an attacker to gain unauthorized access, carry out malicious actions, or compromise the system without the user's awareness.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2023-40660?

It affects 2 products.


Products: Opensc Project Opensc, Redhat Enterprise Linux.

## How do I fix CVE-2023-40660?

Apply the vendor's patch.

## Is CVE-2023-40660 being exploited?

There is no known exploitation of CVE-2023-40660 in the wild and no public exploit code.

## Other vulnerabilities in Opensc Project Opensc

- [CVE-2021-34193](https://insights.sbomify.com/CVE-2021-34193/): Memory corruption in n/a (high 7.5)
- [CVE-2019-16058](https://insights.sbomify.com/CVE-2019-16058/): Memory corruption in n/a (high 7.5)
- [CVE-2019-6502](https://insights.sbomify.com/CVE-2019-6502/): Denial of service in n/a (high 7.5)
- [CVE-2023-2977](https://insights.sbomify.com/CVE-2023-2977/): Memory corruption in OpenSC (high 7.1)
- [CVE-2019-20792](https://insights.sbomify.com/CVE-2019-20792/): Use after free in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-40660 and fix it if it is affected.

What it is: CVE-2023-40660 is a medium-severity authentication bypass vulnerability in Opensc Project Opensc, published on 6 Nov 2023. 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-2023-40660 in the wild and no public exploit code.

Affected product: Opensc Project Opensc. 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-2023-40660/ (Markdown: https://insights.sbomify.com/CVE-2023-40660/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40660
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40660
- OSV: https://osv.dev/vulnerability/CVE-2023-40660

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40660/
Summaries are generated and may contain mistakes; the official description above is the record.