Input validation error in Debian Linux - CVE-2011-4120
Published: November 26, 2019 / Updated: August 8, 2020
Vulnerability identifier: #VU35033
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2011-4120
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.
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.
Affected software
Debian Linux
Fedora
libyubikey
ykclient
pam_yubico
Fedora
libyubikey
ykclient
pam_yubico
How to mitigate CVE-2011-4120
Install update from vendor's website.
libyubikey - update to 1.7-2.el6
ykclient - update to 2.7-1.el6
pam_yubico - update to 2.10-1.el6
ykclient - update to 2.7-1.el6
pam_yubico - update to 2.10-1.el6