Amazon Linux 2 : krb5 (ALAS-2018-1010)

medium Nessus Plugin ID 109689
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Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

Authentication bypass by improper validation of certificate EKU and SAN

An authentication bypass flaw was found in the way krb5's certauth interface handled the validation of client certificates. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary principals under rare and erroneous circumstances.(CVE-2017-7562)

Invalid S4U2Self or S4U2Proxy request causes assertion failure

A denial of service flaw was found in MIT Kerberos krb5kdc service. An authenticated attacker could use this flaw to cause krb5kdc to exit with an assertion failure by making an invalid S4U2Self or S4U2Proxy request.( CVE-2017-11368)

Solution

Run 'yum update krb5' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2018-1010.html

Plugin Details

Severity: Medium

ID: 109689

File Name: al2_ALAS-2018-1010.nasl

Version: 1.1

Type: local

Agent: unix

Published: 5/11/2018

Updated: 5/11/2018

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 4

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

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Vulnerability Information

CPE: cpe:2.3:o:amazon:linux:2:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-devel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-libs:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-pkinit:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-server:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-server-ldap:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:krb5-workstation:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:libkadm5:*:*:*:*:*:*:*

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

Patch Publication Date: 5/10/2018

Reference Information

CVE: CVE-2017-7562, CVE-2017-11368

ALAS: 2018-1010