NetBSD Security Advisory 2015-008: OpenSSL and TLS protocol vulnerabilities
20 August, 2015 by security-officer@NetBSD.org | netbsd
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NetBSD Security Advisory 2015-008
=================================
Topic: OpenSSL and TLS protocol vulnerabilities
Version: NetBSD-current: source prior to July 7th
NetBSD 6.1 - 6.1.5: affected
NetBSD 6.0 - 6.0.6: affected
NetBSD 5.1 - 5.1.4: affected
NetBSD 5.2 - 5.2.2: affected
pkgsrc: affected
Severity: remote DoS, confidentiality compromise
Fixed: NetBSD-current: Jul 7th, 2015
NetBSD-7 branch: Jul 11th, 2015
NetBSD-6-0 branch: Jul 12th, 2015
NetBSD-6-1 branch: Jul 12th, 2015
NetBSD-6 branch: Jul 12th, 2015
NetBSD-5-2 branch: Aug 14th, 2015
NetBSD-5-1 branch: Aug 14th, 2015
NetBSD-5 branch: Aug 14th, 2015
pkgsrc: openssl-1.0.2d corrects these issues
Teeny versions released later than the fix date will contain the fix.
Please note that NetBSD releases prior to 5.1 are no longer supported.
It is recommended that all users upgrade to a supported release.
Abstract
========
This advisory covers the OpenSSL Security Advisory of June 11th, 2015
which lists seven different vulnerabilities that affect NetBSD releases;
also, the OpenSSL Security Advisory of July 9th, 2015 with one vulnerability
that affected only NetBSD-current:
DHE man-in-the-middle protection (Logjam, CVE-2015-4000)
Malformed ECParameters causes infinite loop (CVE-2015-1788)
Exploitable out-of-bounds read in X509_cmp_time (CVE-2015-1789)
PKCS7 crash with missing EnvelopedContent (CVE-2015-1790)
CMS verify infinite loop with unknown hash function (CVE-2015-1792)
Race condition handling NewSessionTicket (CVE-2015-1791)
Invalid free in DTLS (CVE-2014-8176)
and
Alternative chains certificate forgery (CVE-2015-1793)
Also, in NetBSD 5 a regression was introduced October 19th last year
concerning the SSL server code.
Technical Details
=================
See https://www.openssl.org/news/secadv/20150611.txt
and https://www.openssl.org/news/secadv/20150709.txt
The regression in NetBSD 5.* was due to a faulty application
of the POODLE mitigation code, and made the SSL server fail
the client handshake request, with the exception of SSLv3
and TLS1 handshakes where RC4_MD5 was an acceptable cipher,
which would then be the cipher getting used.
In summary this caused a comparably weak cipher to be used
if the connection succeeded as all.
Fixing this problem provides only limited help, though:
Please be aware that while the crypto library from the OpenSSL in
NetBSD 5.x is still ok, that is not true for the ssl library.
The ssl library supports as newest and safest protocol TLS 1.0,
and that is no longer considered good enough. At the same time
we cannot just update OpenSSL on that branch to a newer version
since all available newer ones are incompatible.
Solutions and Workarounds
=========================
Solution:
Update the OpenSSL libraries and restart all affected services.
Users of NetBSD 5.*:
Please consider using OpenSSL from pkgsrc for all uses where you
actually want secure SSL connections.
Programs in that use libssl are: amd, pkgtools, postfix, hostapd,
wpa_supplicant, httpd and the ldap client.
In cases where you use the encrypted communications feature of
these programs across an untrusted medium, using replacements
from pkgsrc is recommended as well.
- From source:
+-----------
Update src and rebuild and install.
For NetBSD-6*, NetBSD-7* and NetBSD-current:
cvs update -dP -r <branch> crypto/external/bsd/openssl
- From tarballs:
+-------------
To obtain fixed binaries, fetch the appropriate base.tgz and comp.tgz
from a daily build later than the fix dates, from
http://nyftp.netbsd.org/pub/NetBSD-daily/<rel>/<date>/<arch>/binary/sets/
with a date later than the fix date for your branch as listed above,
and your release version and architecture
(e.g. http://nyftp.netbsd.org/pub/NetBSD-daily/netbsd-6-1/201503XXXX00Z/amd64/binary/sets/),
and then extract the files:
Shared libraries:
tar xzpf base.tgz \*libssl\* \*libcrypto\*
And static libraries and linker config files:
tar xzpf comp.tgz \*libssl\* \*libcrypto\*
Get the fixed library into use
+-----------------------------
Since the vulnerability is in a shared library, getting the old
library purged and the fixed one into use requires restarting
all programs that load libssl.
The easiest way to do this is to reboot the system.
Another method, using /bin/sh:
ps ax -o pid | (while read pid; do \
pmap $pid | egrep '(libssl|libcrypto)' && echo found $pid ;\
done)
will find non-chrooted programs that have the affected libraries open;
you'll need to restart them.
sshd, ntp and named may not show up in this list since they may
run chrooted and re-exec'ed but they also would need to be restarted.
ldd <programname> will show the shared libraries a program will
want to use.
Thanks To
=========
Thanks to the OpenSSL development team for the advisory and fixes.
OpenSSL also credits:
Joseph Birr-Pixton for reporting CVE-2015-1788
Robert Swiecki (Google) and Hanno Böck for reporting CVE-2015-1789
Michal Zalewski (Google) for reporting CVE-2015-1790
Johannes Bauer for reporting CVE-2015-1792
Praveen Kariyanahalli, Ivan Fratric (Google) and Felix Groebert (Google)
for reporting CVE-2014-8176
Adam Langley (Google/BoringSSL), David Benjamin (Google/BoringSSL) for
reporting CVE-2015-1793
Revision History
================
2015-08-19 Initial release
More Information
================
Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at
http://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2015-008.txt.asc
Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.org/ and http://www.NetBSD.org/Security/ .
Copyright 2015, The NetBSD Foundation, Inc. All Rights Reserved.
Redistribution permitted only in full, unmodified form.
$NetBSD: NetBSD-SA2015-008.txt,v 1.1 2015/08/19 18:15:33 tonnerre Exp $
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