Amazon Linux AMI : openssh (ALAS-2015-625)

High Nessus Plugin ID 87351

Synopsis

The remote Amazon Linux AMI host is missing a security update.

Description

A flaw was found in the way OpenSSH handled PAM authentication when using privilege separation. An attacker with valid credentials on the system and able to fully compromise a non-privileged pre-authentication process using a different flaw could use this flaw to authenticate as other users.

It was discovered that the OpenSSH sshd daemon did not check the list of keyboard-interactive authentication methods for duplicates. A remote attacker could use this flaw to bypass the MaxAuthTries limit, making it easier to perform password guessing attacks.

A use-after-free flaw was found in OpenSSH. An attacker able to fully compromise a non-privileged pre-authentication process using a different flaw could possibly cause sshd to crash or execute arbitrary code with root privileges.

Solution

Run 'yum update openssh' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2015-625.html

Plugin Details

Severity: High

ID: 87351

File Name: ala_ALAS-2015-625.nasl

Version: 2.2

Type: local

Agent: unix

Published: 2015/12/15

Updated: 2018/04/18

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 8.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:openssh, p-cpe:/a:amazon:linux:openssh-clients, p-cpe:/a:amazon:linux:openssh-debuginfo, p-cpe:/a:amazon:linux:openssh-keycat, p-cpe:/a:amazon:linux:openssh-ldap, p-cpe:/a:amazon:linux:openssh-server, p-cpe:/a:amazon:linux:pam_ssh_agent_auth, cpe:/o:amazon:linux

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Patch Publication Date: 2015/12/14

Reference Information

CVE: CVE-2015-5600, CVE-2015-6563, CVE-2015-6564

ALAS: 2015-625