CVE-2020-24387

Name: CVE-2020-24387
Creator: NVD / NIST
Published: 2020-10-19T20:15:12.947+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.73%

Last modified Jun 17, 2026

CVE-2020-24387 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in the yh_create_session() function of yubihsm-shell through 2.0.2. The function does not explicitly check the returned session id from the device. EPSS estimates a 1.73% chance of exploitation in the next 30 days.

Description

An issue was discovered in the yh_create_session() function of yubihsm-shell through 2.0.2. The function does not explicitly check the returned session id from the device. An invalid session id would lead to out-of-bounds read and write operations in the session array. This could be used by an attacker to cause a denial of service attack.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.73%

74.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Yubico	Yubihsm-Shell	<= 2.0.2
Fedoraproject	Fedora	33

References

https://blog.inhq.net/posts/yubico-libyubihsm-vuln/Exploit, Third Party Advisory
https://developers.yubico.com/yubihsm-shell/Vendor Advisory
https://github.com/Yubico/yubihsm-shellThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y77KQJW76M3PFOBFLBT6DLH2NWHYRNZO/
https://www.yubico.com/support/security-advisories/ysa-2020-06/Vendor Advisory
https://blog.inhq.net/posts/yubico-libyubihsm-vuln/Exploit, Third Party Advisory
https://developers.yubico.com/yubihsm-shell/Vendor Advisory
https://github.com/Yubico/yubihsm-shellThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y77KQJW76M3PFOBFLBT6DLH2NWHYRNZO/
https://www.yubico.com/support/security-advisories/ysa-2020-06/Vendor Advisory

Timeline

Published: Oct 19, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-24387?

How severe is CVE-2020-24387?

CVE-2020-24387 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.73% probability of exploitation in the next 30 days.

How do I fix CVE-2020-24387?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-24387?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST