Input validation error in Debian Linux

1) Input validation error

EUVDB-ID: #VU35033

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2011-4120

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Debian Linux: 8.0 - 9.0

CPE2.3

• cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

External links

http://access.redhat.com/security/cve/cve-2011-4120
http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4120
http://security-tracker.debian.org/tracker/CVE-2011-4120
http://www.openwall.com/lists/oss-security/2011/11/07/6

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.