Buffer overflow in Yubico Libu2f-Host

CVE-2018-20340

Yubico libu2f-host 1.1.6 contains unchecked buffers in devs.c, which could enable a malicious token to exploit a buffer overflow. An attacker could use this to attempt to execute malicious code using a crafted USB device masquerading as a security token on a computer where the affected library is currently in use. It is not possible to perform this attack with a genuine YubiKey.

Vulnerability class: Buffer Overflow

EPSS: 0.005 (39.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2018-20340?
CVE-2018-20340 is a medium-severity vulnerability in Yubico Libu2f-Host, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 6.8/10. Published 2019-03-21.
How severe is CVE-2018-20340?
Medium severity. CVSS v3 base score is 6.8 out of 10.