CVE-2018-20340

Publication date 8 February 2019

Last updated 18 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

6.8 · Medium

Score breakdown

Description

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
libu2f-host 25.10 questing
Not affected
25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Fixed 1.1.6-1ubuntu0.1
18.04 LTS bionic
Fixed 1.1.4-1ubuntu0.1
16.04 LTS xenial
Vulnerable
14.04 LTS trusty Not in release

Notes

sbeattie

requires libpam-u2f setup or other yubikey based software applications. Browser U2F implmentations are NOT affected.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
libu2f-host

Severity score breakdown

Parameter Value
Base score 6.8 · Medium
Attack vector Physical
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Other references