CVE-2011-4120

Name: CVE-2011-4120
Creator: NVD / NIST
Published: 2019-11-26T05:15:13.13+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.02%

Last modified Jun 16, 2026

CVE-2011-4120 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Yubico PAM Module before 2.10 performed user authentication when 'use_first_pass' PAM configuration option was not used and the module was configured as 'sufficient' in the PAM configuration. A remote attacker could use this flaw to circumvent common authentication process and obtain access to the account in question by providing a NULL value (pressing Ctrl-D keyboard sequence) as the password string.. EPSS estimates a 2.02% chance of exploitation in the next 30 days.

Description

Yubico PAM Module before 2.10 performed user authentication when 'use_first_pass' PAM configuration option was not used and the module was configured as 'sufficient' in the PAM configuration. A remote attacker could use this flaw to circumvent common authentication process and obtain access to the account in question by providing a NULL value (pressing Ctrl-D keyboard sequence) as the password string.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.02%

78.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Yubico	Pam Module	< 2.10
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0

References

https://access.redhat.com/security/cve/cve-2011-4120Broken Link, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4120Issue Tracking, Patch, Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2011-4120Third Party Advisory
https://www.openwall.com/lists/oss-security/2011/11/07/6Mailing List, Third Party Advisory
https://access.redhat.com/security/cve/cve-2011-4120Broken Link, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4120Issue Tracking, Patch, Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2011-4120Third Party Advisory
https://www.openwall.com/lists/oss-security/2011/11/07/6Mailing List, Third Party Advisory

Timeline

Published: Nov 26, 2019
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2011-4120?

How severe is CVE-2011-4120?

CVE-2011-4120 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.02% probability of exploitation in the next 30 days.

How do I fix CVE-2011-4120?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2011-4120?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST