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Fencer Vulns
high 7.5

CVE-2020-24387 json

An issue was discovered in the yh_create_session() function of yubihsm-shell through 2.0.2.

published 2020-10-19 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-17119

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-24387 updated cvss 6.5

yubihsm-shell: yh_create_session() does not explicitly check the returned session id could result in DoS

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.75% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • blog.inhq.net https://blog.inhq.net/posts/yubico-libyubihsm-vuln/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.