Amazon Linux AMI : ruby (ALAS-2013-173)

This script is Copyright (C) 2013-2014 Tenable Network Security, Inc.


Synopsis :

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

Description :

It was discovered that Ruby's REXML library did not properly restrict
XML entity expansion. An attacker could use this flaw to cause a
denial of service by tricking a Ruby application using REXML to read
text nodes from specially crafted XML content, which will result in
REXML consuming large amounts of system memory. (CVE-2013-1821)

It was found that the RHSA-2011-0910 update did not correctly fix the
CVE-2011-1005 issue, a flaw in the method for translating an exception
message into a string in the Exception class. A remote attacker could
use this flaw to bypass safe level 4 restrictions, allowing untrusted
(tainted) code to modify arbitrary, trusted (untainted) strings, which
safe level 4 restrictions would otherwise prevent. (CVE-2012-4481)

The safe-level feature in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through
1.8.7-330, and 1.8.8dev allows context-dependent attackers to modify
strings via the Exception#to_s method, as demonstrated by changing an
intended pathname. (CVE-2011-1005)

See also :

http://www.nessus.org/u?dbee69ee

Solution :

Run 'yum update ruby' to update your system.

Risk factor :

Medium / CVSS Base Score : 5.0
(CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N)

Family: Amazon Linux Local Security Checks

Nessus Plugin ID: 69732 ()

Bugtraq ID:

CVE ID: CVE-2011-1005
CVE-2012-4481
CVE-2013-1821