ALAS-2015-624


Amazon Linux AMI Security Advisory: ALAS-2015-624
Advisory Release Date: 2015-12-13 14:23 Pacific
Severity: Medium

Issue Overview:

A flaw was found in the OTP kdcpreauth module of MIT Kerberos. A remote attacker could use this flaw to bypass the requires_preauth flag on a client principal and obtain a ciphertext encrypted in the principal's long-term key. This ciphertext could be used to conduct an off-line dictionary attack against the user's password.

It was found that the krb5_read_message() function of MIT Kerberos did not correctly sanitize input, and could create invalid krb5_data objects. A remote, unauthenticated attacker could use this flaw to crash a Kerberos child process via a specially crafted request.


Affected Packages:

krb5


Issue Correction:
Run yum update krb5 to update your system.

New Packages:
i686:
    krb5-server-1.13.2-10.39.amzn1.i686
    krb5-libs-1.13.2-10.39.amzn1.i686
    krb5-debuginfo-1.13.2-10.39.amzn1.i686
    krb5-workstation-1.13.2-10.39.amzn1.i686
    krb5-server-ldap-1.13.2-10.39.amzn1.i686
    krb5-devel-1.13.2-10.39.amzn1.i686
    krb5-pkinit-openssl-1.13.2-10.39.amzn1.i686

src:
    krb5-1.13.2-10.39.amzn1.src

x86_64:
    krb5-devel-1.13.2-10.39.amzn1.x86_64
    krb5-pkinit-openssl-1.13.2-10.39.amzn1.x86_64
    krb5-debuginfo-1.13.2-10.39.amzn1.x86_64
    krb5-server-1.13.2-10.39.amzn1.x86_64
    krb5-workstation-1.13.2-10.39.amzn1.x86_64
    krb5-libs-1.13.2-10.39.amzn1.x86_64
    krb5-server-ldap-1.13.2-10.39.amzn1.x86_64