OpenSSL CHANGES
_______________
- Changes between 1.0.2d and 1.0.2e [xx XXX xxxx]
+ Changes between 1.0.2f and 1.0.2g [1 Mar 2016]
+
+ * Disable weak ciphers in SSLv3 and up in default builds of OpenSSL.
+ Builds that are not configured with "enable-weak-ssl-ciphers" will not
+ provide any "EXPORT" or "LOW" strength ciphers.
+ [Viktor Dukhovni]
+
+ * Disable SSLv2 default build, default negotiation and weak ciphers. SSLv2
+ is by default disabled at build-time. Builds that are not configured with
+ "enable-ssl2" will not support SSLv2. Even if "enable-ssl2" is used,
+ users who want to negotiate SSLv2 via the version-flexible SSLv23_method()
+ will need to explicitly call either of:
+
+ SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2);
+ or
+ SSL_clear_options(ssl, SSL_OP_NO_SSLv2);
+
+ as appropriate. Even if either of those is used, or the application
+ explicitly uses the version-specific SSLv2_method() or its client and
+ server variants, SSLv2 ciphers vulnerable to exhaustive search key
+ recovery have been removed. Specifically, the SSLv2 40-bit EXPORT
+ ciphers, and SSLv2 56-bit DES are no longer available.
+ (CVE-2016-0800)
+ [Viktor Dukhovni]
+
+ *) Fix a double-free in DSA code
+
+ A double free bug was discovered when OpenSSL parses malformed DSA private
+ keys and could lead to a DoS attack or memory corruption for applications
+ that receive DSA private keys from untrusted sources. This scenario is
+ considered rare.
+
+ This issue was reported to OpenSSL by Adam Langley(Google/BoringSSL) using
+ libFuzzer.
+ (CVE-2016-0705)
+ [Stephen Henson]
+
+ *) Disable SRP fake user seed to address a server memory leak.
+
+ Add a new method SRP_VBASE_get1_by_user that handles the seed properly.
+
+ SRP_VBASE_get_by_user had inconsistent memory management behaviour.
+ In order to fix an unavoidable memory leak, SRP_VBASE_get_by_user
+ was changed to ignore the "fake user" SRP seed, even if the seed
+ is configured.
+
+ Users should use SRP_VBASE_get1_by_user instead. Note that in
+ SRP_VBASE_get1_by_user, caller must free the returned value. Note
+ also that even though configuring the SRP seed attempts to hide
+ invalid usernames by continuing the handshake with fake
+ credentials, this behaviour is not constant time and no strong
+ guarantees are made that the handshake is indistinguishable from
+ that of a valid user.
+ (CVE-2016-0798)
+ [Emilia Käsper]
+
+ *) Fix BN_hex2bn/BN_dec2bn NULL pointer deref/heap corruption
+
+ In the BN_hex2bn function the number of hex digits is calculated using an
+ int value |i|. Later |bn_expand| is called with a value of |i * 4|. For
+ large values of |i| this can result in |bn_expand| not allocating any
+ memory because |i * 4| is negative. This can leave the internal BIGNUM data
+ field as NULL leading to a subsequent NULL ptr deref. For very large values
+ of |i|, the calculation |i * 4| could be a positive value smaller than |i|.
+ In this case memory is allocated to the internal BIGNUM data field, but it
+ is insufficiently sized leading to heap corruption. A similar issue exists
+ in BN_dec2bn. This could have security consequences if BN_hex2bn/BN_dec2bn
+ is ever called by user applications with very large untrusted hex/dec data.
+ This is anticipated to be a rare occurrence.
+
+ All OpenSSL internal usage of these functions use data that is not expected
+ to be untrusted, e.g. config file data or application command line
+ arguments. If user developed applications generate config file data based
+ on untrusted data then it is possible that this could also lead to security
+ consequences. This is also anticipated to be rare.
+
+ This issue was reported to OpenSSL by Guido Vranken.
+ (CVE-2016-0797)
+ [Matt Caswell]
+
+ *) Fix memory issues in BIO_*printf functions
+
+ The internal |fmtstr| function used in processing a "%s" format string in
+ the BIO_*printf functions could overflow while calculating the length of a
+ string and cause an OOB read when printing very long strings.
+
+ Additionally the internal |doapr_outch| function can attempt to write to an
+ OOB memory location (at an offset from the NULL pointer) in the event of a
+ memory allocation failure. In 1.0.2 and below this could be caused where
+ the size of a buffer to be allocated is greater than INT_MAX. E.g. this
+ could be in processing a very long "%s" format string. Memory leaks can
+ also occur.
+
+ The first issue may mask the second issue dependent on compiler behaviour.
+ These problems could enable 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 be vulnerable. OpenSSL itself uses these
+ functions when printing out human-readable dumps of ASN.1 data. Therefore
+ applications that print this data could be vulnerable if the data is from
+ untrusted sources. OpenSSL command line applications could also be
+ vulnerable where they print out ASN.1 data, or if untrusted data is passed
+ as command line arguments.
+
+ Libssl is not considered directly vulnerable. Additionally certificates etc
+ received via remote connections via libssl are also unlikely to be able to
+ trigger these issues because of message size limits enforced within libssl.
+
+ This issue was reported to OpenSSL Guido Vranken.
+ (CVE-2016-0799)
+ [Matt Caswell]
+
+ *) Side channel attack on modular exponentiation
- *)
+ A side-channel attack was found which makes use of cache-bank conflicts on
+ the Intel Sandy-Bridge microarchitecture which could lead to the recovery
+ of RSA keys. The ability to exploit this issue is limited as it relies on
+ an attacker who has control of code in a thread running on the same
+ hyper-threaded core as the victim thread which is performing decryptions.
+
+ This issue was reported to OpenSSL by Yuval Yarom, The University of
+ Adelaide and NICTA, Daniel Genkin, Technion and Tel Aviv University, and
+ Nadia Heninger, University of Pennsylvania with more information at
+ http://cachebleed.info.
+ (CVE-2016-0702)
+ [Andy Polyakov]
+
+ *) Change the req app to generate a 2048-bit RSA/DSA key by default,
+ if no keysize is specified with default_bits. This fixes an
+ omission in an earlier change that changed all RSA/DSA key generation
+ apps to use 2048 bits by default.
+ [Emilia Käsper]
+
+ Changes between 1.0.2e and 1.0.2f [28 Jan 2016]
+
+ *) DH small subgroups
+
+ Historically OpenSSL only ever generated DH parameters based on "safe"
+ primes. More recently (in version 1.0.2) support was provided for
+ generating X9.42 style parameter files such as those required for RFC 5114
+ support. The primes used in such files may not be "safe". Where an
+ application is using DH configured with parameters based on primes that are
+ not "safe" then an attacker could use this fact to find a peer's private
+ DH exponent. This attack requires that the attacker complete multiple
+ handshakes in which the peer uses the same private DH exponent. For example
+ this could be used to discover a TLS server's private DH exponent if it's
+ reusing the private DH exponent or it's using a static DH ciphersuite.
+
+ OpenSSL provides the option SSL_OP_SINGLE_DH_USE for ephemeral DH (DHE) in
+ TLS. It is not on by default. If the option is not set then the server
+ reuses the same private DH exponent for the life of the server process and
+ would be vulnerable to this attack. It is believed that many popular
+ applications do set this option and would therefore not be at risk.
+
+ The fix for this issue adds an additional check where a "q" parameter is
+ available (as is the case in X9.42 based parameters). This detects the
+ only known attack, and is the only possible defense for static DH
+ ciphersuites. This could have some performance impact.
+
+ Additionally the SSL_OP_SINGLE_DH_USE option has been switched on by
+ default and cannot be disabled. This could have some performance impact.
+
+ This issue was reported to OpenSSL by Antonio Sanso (Adobe).
+ (CVE-2016-0701)
+ [Matt Caswell]
+
+ *) SSLv2 doesn't block disabled ciphers
+
+ A malicious client can negotiate SSLv2 ciphers that have been disabled on
+ the server and complete SSLv2 handshakes even if all SSLv2 ciphers have
+ been disabled, provided that the SSLv2 protocol was not also disabled via
+ SSL_OP_NO_SSLv2.
+
+ This issue was reported to OpenSSL on 26th December 2015 by Nimrod Aviram
+ and Sebastian Schinzel.
+ (CVE-2015-3197)
+ [Viktor Dukhovni]
+
+ *) Reject DH handshakes with parameters shorter than 1024 bits.
+ [Kurt Roeckx]
+
+ Changes between 1.0.2d and 1.0.2e [3 Dec 2015]
+
+ *) BN_mod_exp may produce incorrect results on x86_64
+
+ There is a carry propagating bug in the x86_64 Montgomery squaring
+ procedure. No EC algorithms are affected. Analysis suggests that attacks
+ against RSA and DSA as a result of this defect would be very difficult to
+ perform and are not believed likely. Attacks against DH are considered just
+ feasible (although very difficult) because most of the work necessary to
+ deduce information about a private key may be performed offline. The amount
+ of resources required for such an attack would be very significant and
+ likely only accessible to a limited number of attackers. An attacker would
+ additionally need online access to an unpatched system using the target
+ private key in a scenario with persistent DH parameters and a private
+ key that is shared between multiple clients. For example this can occur by
+ default in OpenSSL DHE based SSL/TLS ciphersuites.
+
+ This issue was reported to OpenSSL by Hanno Böck.
+ (CVE-2015-3193)
+ [Andy Polyakov]
+
+ *) Certificate verify crash with missing PSS parameter
+
+ The signature verification routines will crash with a NULL pointer
+ dereference if presented with an ASN.1 signature using the RSA PSS
+ algorithm and absent mask generation function parameter. Since these
+ routines are used to verify certificate signature algorithms this can be
+ used to crash any certificate verification operation and exploited in a
+ DoS attack. Any application which performs certificate verification is
+ vulnerable including OpenSSL clients and servers which enable client
+ authentication.
+
+ This issue was reported to OpenSSL by Loïc Jonas Etienne (Qnective AG).
+ (CVE-2015-3194)
+ [Stephen Henson]
+
+ *) X509_ATTRIBUTE memory leak
+
+ When presented with a malformed X509_ATTRIBUTE structure OpenSSL will leak
+ memory. This structure is used by the PKCS#7 and CMS routines so any
+ application which reads PKCS#7 or CMS data from untrusted sources is
+ affected. SSL/TLS is not affected.
+
+ This issue was reported to OpenSSL by Adam Langley (Google/BoringSSL) using
+ libFuzzer.
+ (CVE-2015-3195)
+ [Stephen Henson]
+
+ *) Rewrite EVP_DecodeUpdate (base64 decoding) to fix several bugs.
+ This changes the decoding behaviour for some invalid messages,
+ though the change is mostly in the more lenient direction, and
+ legacy behaviour is preserved as much as possible.
+ [Emilia Käsper]
+
+ *) In DSA_generate_parameters_ex, if the provided seed is too short,
+ use a random seed, as already documented.
+ [Rich Salz and Ismo Puustinen <ismo.puustinen@intel.com>]
Changes between 1.0.2c and 1.0.2d [9 Jul 2015]
This issue was reported to OpenSSL by Adam Langley/David Benjamin
(Google/BoringSSL).
+ (CVE-2015-1793)
[Matt Caswell]
+ *) Race condition handling PSK identify hint
+
+ If PSK identity hints are received by a multi-threaded client then
+ the values are wrongly updated in the parent SSL_CTX structure. This can
+ result in a race condition potentially leading to a double free of the
+ identify hint data.
+ (CVE-2015-3196)
+ [Stephen Henson]
+
Changes between 1.0.2b and 1.0.2c [12 Jun 2015]
*) Fix HMAC ABI incompatibility. The previous version introduced an ABI
Changes between 1.0.1l and 1.0.2 [22 Jan 2015]
+ *) Change RSA and DH/DSA key generation apps to generate 2048-bit
+ keys by default.
+ [Kurt Roeckx]
+
*) Facilitate "universal" ARM builds targeting range of ARM ISAs, e.g.
ARMv5 through ARMv8, as opposite to "locking" it to single one.
So far those who have to target multiple plaforms would compromise
[mancha <mancha1@zoho.com>]
*) Fix eckey_priv_encode so it immediately returns an error upon a failure
- in i2d_ECPrivateKey.
+ in i2d_ECPrivateKey. Thanks to Ted Unangst for feedback on this issue.
[mancha <mancha1@zoho.com>]
*) Fix some double frees. These are not thought to be exploitable.
projects / openssl.git / blobdiff