U radu programskog paketa ruby uočeni su i ispravljeni višestruki nedostaci koje udaljeni napadač može iskoristiti za izvođenje DoS napada ili predviđanje vrijednosti koje vraća generator slučajnih brojeva.
Paket:
ruby 1.x
Operacijski sustavi:
Red Hat Enterprise Linux 4, Red Hat Enterprise Linux 5
Kritičnost:
6.8
Problem:
pogreška u programskoj funkciji, pogreška u programskoj komponenti
Propusti su uzrokovani pogreškom u izračunu hash vrijednosti te ne provođenju ponovne inicijalizacije generatora slučajnih brojeva nakon grananja procesa.
Posljedica:
Napadač može iskoristiti ranjivosti za izvođenje napada uskraćivanja usluge (DoS) podmetanjem posebno oblikovanih ulaznih podataka aplikaciji koja sprema hash tablicu ili za predviđanje vrijednosti koje vraća generator slučajnih brojeva.
Rješenje:
Svim korisnicima se savjetuje korištenje programske nadogradnje koja otklanja opisane propuste.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
=====================================================================
Red Hat Security Advisory
Synopsis: Moderate: ruby security update
Advisory ID: RHSA-2012:0070-01
Product: Red Hat Enterprise Linux
Advisory URL: https://rhn.redhat.com/errata/RHSA-2012-0070.html
Issue date: 2012-01-30
CVE Names: CVE-2011-3009 CVE-2011-4815
=====================================================================
1. Summary:
Updated ruby packages that fix two security issues are now available for
Red Hat Enterprise Linux 4 and 5.
The Red Hat Security Response Team has rated this update as having moderate
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.
2. Relevant releases/architectures:
RHEL Desktop Workstation (v. 5 client) - i386, x86_64
Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64
Red Hat Enterprise Linux AS version 4 - i386, ia64, ppc, s390, s390x, x86_64
Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64
Red Hat Enterprise Linux Desktop version 4 - i386, x86_64
Red Hat Enterprise Linux ES version 4 - i386, ia64, x86_64
Red Hat Enterprise Linux WS version 4 - i386, ia64, x86_64
3. Description:
Ruby is an extensible, interpreted, object-oriented, scripting language. It
has features to process text files and to do system management tasks.
A denial of service flaw was found in the implementation of associative
arrays (hashes) in Ruby. An attacker able to supply a large number of
inputs to a Ruby application (such as HTTP POST request parameters sent to
a web application) that are used as keys when inserting data into an array
could trigger multiple hash function collisions, making array operations
take an excessive amount of CPU time. To mitigate this issue, randomization
has been added to the hash function to reduce the chance of an attacker
successfully causing intentional collisions. (CVE-2011-4815)
It was found that Ruby did not reinitialize the PRNG (pseudorandom number
generator) after forking a child process. This could eventually lead to the
PRNG returning the same result twice. An attacker keeping track of the
values returned by one child process could use this flaw to predict the
values the PRNG would return in other child processes (as long as the
parent process persisted). (CVE-2011-3009)
Red Hat would like to thank oCERT for reporting CVE-2011-4815. oCERT
acknowledges Julian WÄ
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