Vulnerability identifier: #VU32409

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-3238

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
linux-pam
Other software / Other software solutions

Vendor: git.kernel.org

Description

The vulnerability allows a remote non-authenticated attacker to #BASIC_IMPACT#.

The _unix_run_helper_binary function in the pam_unix module in Linux-PAM (aka pam) before 1.2.1, when unable to directly access passwords, allows local users to enumerate usernames or cause a denial of service (hang) via a large password.

Mitigation
Install update from vendor's website.

Vulnerable software versions

linux-pam: 1.1.3 - 1.1.8

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External links
http://lists.fedoraproject.org/pipermail/package-announce/2015-July/161350.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-June/161249.html
http://rhn.redhat.com/errata/RHSA-2015-1640.html
http://www.openwall.com/lists/oss-security/2015/06/25/13
http://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html
http://www.securityfocus.com/bid/75428
http://www.ubuntu.com/usn/USN-2935-1
http://www.ubuntu.com/usn/USN-2935-2
http://www.ubuntu.com/usn/USN-2935-3
http://bugzilla.redhat.com/show_bug.cgi?id=1228571
http://security.gentoo.org/glsa/201605-05
http://www.trustwave.com/Resources/Security-Advisories/Advisories/TWSL2015-011/?fid=6551
http://www.trustwave.com/Resources/SpiderLabs-Blog/Username-Enumeration-against-OpenSSH-SELinux-with-CVE-2015-3238/

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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.