HOMEVULNERABILITIESCVE-2020-24387
HIGH

CVE-2020-24387

CWE-125Published: October 19, 2020· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-24387 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Fedora1 product(s)
fedora
yubico1 product(s)
yubihsm-shell
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://blog.inhq.net/posts/yubico-libyubihsm-vuln/
ADVISORYhttps://developers.yubico.com/yubihsm-shell/
ADVISORYhttps://github.com/Yubico/yubihsm-shell
ADVISORYhttps://www.yubico.com/support/security-advisories/ysa-2020-06/
ADVISORYhttps://blog.inhq.net/posts/yubico-libyubihsm-vuln/
ADVISORYhttps://developers.yubico.com/yubihsm-shell/
ADVISORYhttps://github.com/Yubico/yubihsm-shell
ADVISORYhttps://www.yubico.com/support/security-advisories/ysa-2020-06/

All References (10)

→
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

Quick Facts

CVE IDCVE-2020-24387
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-125
CISA KEVNo
Affected2 vendor(s)
PublishedOct 19, 2020

Related CVEs (CWE-125)

CVE-2021-41556
10.0
CVE-2017-14451
10.0
CVE-2026-24826
10.0
CVE-2013-0767
10.0
CVE-2009-2523
10.0
CVE-2021-21777
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-24387 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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