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Sigurnosni nedostaci programskog paketa openssl

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FreeBSD-SA-14:23.openssl Security Advisory
The FreeBSD Project

Topic: OpenSSL multiple vulnerabilities

Category: contrib
Module: openssl
Announced: 2014-10-21
Affects: All supported versions of FreeBSD.
Corrected: 2014-10-15 19:59:43 UTC (stable/10, 10.1-PRERELEASE)
2014-10-21 19:00:32 UTC (releng/10.1, 10.1-RC3)
2014-10-21 19:00:32 UTC (releng/10.1, 10.1-RC2-p1)
2014-10-21 19:00:32 UTC (releng/10.1, 10.1-RC1-p1)
2014-10-21 19:00:32 UTC (releng/10.1, 10.1-BETA3-p1)
2014-10-21 20:21:10 UTC (releng/10.0, 10.0-RELEASE-p10)
2014-10-15 20:28:31 UTC (stable/9, 9.3-STABLE)
2014-10-21 20:21:10 UTC (releng/9.3, 9.3-RELEASE-p3)
2014-10-21 20:21:10 UTC (releng/9.2, 9.2-RELEASE-p13)
2014-10-21 20:21:10 UTC (releng/9.1, 9.1-RELEASE-p20)
2014-10-15 20:28:31 UTC (stable/8, 8.4-STABLE)
2014-10-21 20:21:27 UTC (releng/8.4, 8.4-RELEASE-p17)
CVE Name: CVE-2014-3513, CVE-2014-3566, CVE-2014-3567, CVE-2014-3568

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:>.

I. Background

FreeBSD includes software from the OpenSSL Project. The OpenSSL Project is
a collaborative effort to develop a robust, commercial-grade, full-featured
Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3)
and Transport Layer Security (TLS v1) protocols as well as a full-strength
general purpose cryptography library.

II. Problem Description

A flaw in the DTLS SRTP extension parsing code allows an attacker, who
sends a carefully crafted handshake message, to cause OpenSSL to fail
to free up to 64k of memory causing a memory leak. [CVE-2014-3513].

When an OpenSSL SSL/TLS/DTLS server receives a session ticket the
integrity of that ticket is first verified. In the event of a session
ticket integrity check failing, OpenSSL will fail to free memory
causing a memory leak. [CVE-2014-3567].

The SSL protocol 3.0, as supported in OpenSSL and other products, supports
CBC mode encryption where it could not adequately check the integrity of
padding, because of the use of non-deterministic CBC padding. This
protocol weakness makes it possible for an attacker to obtain clear text
data through a padding-oracle attack.

Some client applications (such as browsers) will reconnect using a
downgraded protocol to work around interoperability bugs in older
servers. This could be exploited by an active man-in-the-middle to
downgrade connections to SSL 3.0 even if both sides of the connection
support higher protocols. SSL 3.0 contains a number of weaknesses
including POODLE [CVE-2014-3566].

OpenSSL has added support for TLS_FALLBACK_SCSV to allow applications
to block the ability for a MITM attacker to force a protocol downgrade.

When OpenSSL is configured with “no-ssl3” as a build option, servers
could accept and complete a SSL 3.0 handshake, and clients could be
configured to send them. [CVE-2014-3568].

III. Impact

A remote attacker can cause Denial of Service with OpenSSL 1.0.1
server implementations for both SSL/TLS and DTLS regardless of
whether SRTP is used or configured. [CVE-2014-3513]

By sending a large number of invalid session tickets an attacker
could exploit this issue in a Denial Of Service attack.

An active man-in-the-middle attacker can force a protocol downgrade
to SSLv3 and exploit the weakness of SSLv3 to obtain clear text data
from the connection. [CVE-2014-3566] [CVE-2014-3568]

IV. Workaround

No workaround is available.

V. Solution

Perform one of the following:

1) Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.

2) To update your vulnerable system via a binary patch:

Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

3) To update your vulnerable system via a source code patch:

The following patches have been verified to apply to the applicable
FreeBSD release branches.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

[FreeBSD 10.0]
# fetch
# fetch
# gpg –verify openssl-10.0.patch.asc

[FreeBSD 9.3]
# fetch
# fetch
# gpg –verify openssl-9.3.patch.asc

[FreeBSD 8.4, 9.1 and 9.2]
# fetch
# fetch
# gpg –verify openssl-8.4.patch.asc

b) Apply the patch. Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

c) Recompile the operating system using buildworld and installworld as
described in <URL:>.

Restart all deamons using the library, or reboot the system.

VI. Correction details

The following list contains the correction revision numbers for each
affected branch.

Branch/path Revision
– ————————————————————————-
stable/8/ r273151
releng/8.4/ r273416
stable/9/ r273151
releng/9.1/ r273415
releng/9.2/ r273415
releng/9.3/ r273415
stable/10/ r273149
releng/10.0/ r273415
releng/10.1/ r273399
– ————————————————————————-

To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:

# svn diff -cNNNNNN –summarize svn://

Or visit the following URL, replacing NNNNNN with the revision number:


VII. References





The latest revision of this advisory is available at
Version: GnuPG v1

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AutorMarijo Plepelic
Cert idNCERT-REF-2014-10-0035-ADV
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