[security-announce] openSUSE-SU-2016:0638-1: important: Security update for openssl

[news 28]

openSUSE Security Update: Security update for openssl

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Announcement ID: openSUSE-SU-2016:0638-1

Rating: important

References:

Affected Products:

openSUSE 13.1

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An update that contains security fixes can now be installed.

 

Description:

 

 

This update for openssl fixes various security issues:

 

Security issues fixed:

- CVE-2016-0800 aka the "DROWN" attack (bsc#968046): OpenSSL was

vulnerable to a cross-protocol attack that could lead to decryption of

TLS sessions by using a server supporting SSLv2 and EXPORT cipher suites

as a Bleichenbacher RSA padding oracle.

 

This update changes the openssl library to:

 

* Disable SSLv2 protocol support by default.

 

This can be overridden by setting the environment variable

"OPENSSL_ALLOW_SSL2" or by using SSL_CTX_clear_options using the

SSL_OP_NO_SSLv2 flag.

 

Note that various services and clients had already disabled SSL

protocol 2 by default previously.

 

* Disable all weak EXPORT ciphers by default. These can be reenabled if

required by old legacy software using the environment variable

"OPENSSL_ALLOW_EXPORT".

 

- CVE-2016-0702 aka the "CacheBleed" attack. (bsc#968050) Various changes

in the modular exponentation code were added that make sure that it is

not possible to recover RSA secret keys by analyzing cache-bank

conflicts on the Intel Sandy-Bridge microarchitecture.

 

Note that this was only exploitable if the malicious code was running

on the same hyper threaded Intel Sandy Bridge processor as the victim

thread performing decryptions.

 

- CVE-2016-0705 (bnc#968047): A double free() bug in the DSA ASN1 parser

code was fixed that could be abused to facilitate a denial-of-service

attack.

 

- CVE-2016-0797 (bnc#968048): The BN_hex2bn() and BN_dec2bn() functions

had a bug that could result in an attempt to de-reference a NULL pointer

leading to crashes. This could have security consequences if these

functions were ever called by user applications with large untrusted

hex/decimal data. Also, internal usage of these functions in OpenSSL

uses data from config files or application command line arguments. If

user developed applications generated config file data based on

untrusted data, then this could have had security consequences as well.

 

- CVE-2016-0798 (bnc#968265) The SRP user database lookup method

SRP_VBASE_get_by_user() had a memory leak that attackers could abuse to

facility DoS attacks. To mitigate the issue, the seed handling in

SRP_VBASE_get_by_user() was disabled even if the user has configured a

seed. Applications are advised to migrate to SRP_VBASE_get1_by_user().

 

- CVE-2016-0799 (bnc#968374) On many 64 bit systems, the internal fmtstr()

and doapr_outch() functions could miscalculate the length of a string

and attempt to access out-of-bounds memory locations. These problems

could have enabled attacks where large amounts of untrusted data is

passed to the BIO_*printf functions. If applications use these functions

in this way then they could have been vulnerable. OpenSSL itself uses

these functions when printing out human-readable dumps of ASN.1 data.

Therefore applications that print this data could have been vulnerable

if the data is from untrusted sources. OpenSSL command line applications

could also have been vulnerable when they print out ASN.1 data, or if

untrusted data is passed as command line arguments. Libssl is not

considered directly vulnerable.

 

- CVE-2015-3197 (bsc#963415): The SSLv2 protocol did not block disabled

ciphers.

 

Note that the March 1st 2016 release also references following CVEs that

were fixed by us with CVE-2015-0293 in 2015:

 

- CVE-2016-0703 (bsc#968051): This issue only affected versions of OpenSSL

prior to March 19th 2015 at which time the code was refactored to

address vulnerability CVE-2015-0293. It would have made the above

"DROWN" attack much easier.

- CVE-2016-0704 (bsc#968053): "Bleichenbacher oracle in SSLv2" This issue

only affected versions of OpenSSL prior to March 19th 2015 at which time

the code was refactored to address vulnerability CVE-2015-0293. It would

have made the above "DROWN" attack much easier.

 

 

Patch Instructions:

 

To install this openSUSE Security Update use YaST online_update.

Alternatively you can run the command listed for your product:

 

- openSUSE 13.1:

 

zypper in -t patch 2016-292=1

 

To bring your system up-to-date, use "zypper patch".

 

 

Package List:

 

- openSUSE 13.1 (i586 x86_64):

 

libopenssl-devel-1.0.1k-11.84.1

libopenssl1_0_0-1.0.1k-11.84.1

libopenssl1_0_0-debuginfo-1.0.1k-11.84.1

openssl-1.0.1k-11.84.1

openssl-debuginfo-1.0.1k-11.84.1

openssl-debugsource-1.0.1k-11.84.1

 

- openSUSE 13.1 (x86_64):

 

libopenssl-devel-32bit-1.0.1k-11.84.1

libopenssl1_0_0-32bit-1.0.1k-11.84.1

libopenssl1_0_0-debuginfo-32bit-1.0.1k-11.84.1

 

- openSUSE 13.1 (noarch):

 

openssl-doc-1.0.1k-11.84.1

 

 

References:

 

 

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