Amazon Linux 1 Security Advisory: ALAS-2015-625
Advisory Release Date: 2015-12-14 10:00 Pacific
Advisory Updated Date: 2015-12-13 14:24 Pacific
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.
Affected Packages:
openssh
Issue Correction:
Run yum update openssh to update your system.
i686:
openssh-6.6.1p1-22.58.amzn1.i686
openssh-server-6.6.1p1-22.58.amzn1.i686
pam_ssh_agent_auth-0.9.3-9.22.58.amzn1.i686
openssh-keycat-6.6.1p1-22.58.amzn1.i686
openssh-ldap-6.6.1p1-22.58.amzn1.i686
openssh-debuginfo-6.6.1p1-22.58.amzn1.i686
openssh-clients-6.6.1p1-22.58.amzn1.i686
src:
openssh-6.6.1p1-22.58.amzn1.src
x86_64:
openssh-6.6.1p1-22.58.amzn1.x86_64
openssh-clients-6.6.1p1-22.58.amzn1.x86_64
pam_ssh_agent_auth-0.9.3-9.22.58.amzn1.x86_64
openssh-server-6.6.1p1-22.58.amzn1.x86_64
openssh-debuginfo-6.6.1p1-22.58.amzn1.x86_64
openssh-keycat-6.6.1p1-22.58.amzn1.x86_64
openssh-ldap-6.6.1p1-22.58.amzn1.x86_64