[security-announce] SUSE-SU-2016:0631-1: important: Security update for compat-openssl097g

news · March 2, 2016

SUSE Security Update: Security update for compat-openssl097g

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Announcement ID: SUSE-SU-2016:0631-1

Rating: important

References: #963415 #968046 #968048 #968051 #968053 #968374

Cross-References: CVE-2015-3197 CVE-2016-0702 CVE-2016-0703

CVE-2016-0797 CVE-2016-0799 CVE-2016-0800

Affected Products:

SUSE Linux Enterprise Server for SAP 11-SP4

SUSE Linux Enterprise Desktop 11-SP4

SUSE Linux Enterprise Debuginfo 11-SP4

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An update that fixes 6 vulnerabilities is now available.

Description:

This update for compat-openssl097g fixes the following issues:

- 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-2016-0705 (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-2016-0799 (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.