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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.005 (40.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Yubico Libu2f-Host — versions 1.1.6
- Debian Linux — versions 9.0
Weakness classification (CWE)
References
- seclists.org/bugtraq/2019/Feb/23 (Mailing List, Third Party Advisory)
- www.debian.org/security/2019/dsa-4389 (Third Party Advisory)
- www.yubico.com/support/security-advisories/ysa-2019-01/ (Patch, Vendor Advisory)
- developers.yubico.com/libu2f-host/Release_Notes.html (Release Notes, Vendor Advisory)
- blog.inhq.net/posts/yubico-libu2f-host-vuln-part1/
- security.gentoo.org/glsa/202004-15 (vendor-advisory)
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.