What’s Vulnerable › Vulnerabilities

CVE-2021-43399

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-12-08 · updated 2026-06-17
• Weakness: CWE-787

Description

The Yubico YubiHSM YubiHSM2 library 2021.08, included in the yubihsm-shell project, does not properly validate the length of some operations including SSH signing requests, and some data operations received from a YubiHSM 2 device.

Affected products

• Yubico Yubihsm 2 Software Development Kit: through 2021.08

References

• https://blog.inhq.net/posts/yubico-yubihsm-shell-vuln3/
• https://www.yubico.com/support/security-advisories/ysa-2021-04/
• https://blog.inhq.net/posts/yubico-yubihsm-shell-vuln3/
• https://www.yubico.com/support/security-advisories/ysa-2021-04/

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