+ *) New -noct, -requestct, -requirect and -ctlogfile options for s_client.
+ These allow SCTs (signed certificate timestamps) to be requested and
+ validated when establishing a connection.
+ [Rob Percival <robpercival@google.com>]
+
+ Changes between 1.0.2g and 1.0.2h [3 May 2016]
+
+ *) Prevent padding oracle in AES-NI CBC MAC check
+
+ A MITM attacker can use a padding oracle attack to decrypt traffic
+ when the connection uses an AES CBC cipher and the server support
+ AES-NI.
+
+ This issue was introduced as part of the fix for Lucky 13 padding
+ attack (CVE-2013-0169). The padding check was rewritten to be in
+ constant time by making sure that always the same bytes are read and
+ compared against either the MAC or padding bytes. But it no longer
+ checked that there was enough data to have both the MAC and padding
+ bytes.
+
+ This issue was reported by Juraj Somorovsky using TLS-Attacker.
+ (CVE-2016-2107)
+ [Kurt Roeckx]
+
+ *) Fix EVP_EncodeUpdate overflow
+
+ An overflow can occur in the EVP_EncodeUpdate() function which is used for
+ Base64 encoding of binary data. If an attacker is able to supply very large
+ amounts of input data then a length check can overflow resulting in a heap
+ corruption.
+
+ Internally to OpenSSL the EVP_EncodeUpdate() function is primarily used by
+ the PEM_write_bio* family of functions. These are mainly used within the
+ OpenSSL command line applications, so any application which processes data
+ from an untrusted source and outputs it as a PEM file should be considered
+ vulnerable to this issue. User applications that call these APIs directly
+ with large amounts of untrusted data may also be vulnerable.
+
+ This issue was reported by Guido Vranken.
+ (CVE-2016-2105)
+ [Matt Caswell]
+
+ *) Fix EVP_EncryptUpdate overflow
+
+ An overflow can occur in the EVP_EncryptUpdate() function. If an attacker
+ is able to supply very large amounts of input data after a previous call to
+ EVP_EncryptUpdate() with a partial block then a length check can overflow
+ resulting in a heap corruption. Following an analysis of all OpenSSL
+ internal usage of the EVP_EncryptUpdate() function all usage is one of two
+ forms. The first form is where the EVP_EncryptUpdate() call is known to be
+ the first called function after an EVP_EncryptInit(), and therefore that
+ specific call must be safe. The second form is where the length passed to
+ EVP_EncryptUpdate() can be seen from the code to be some small value and
+ therefore there is no possibility of an overflow. Since all instances are
+ one of these two forms, it is believed that there can be no overflows in
+ internal code due to this problem. It should be noted that
+ EVP_DecryptUpdate() can call EVP_EncryptUpdate() in certain code paths.
+ Also EVP_CipherUpdate() is a synonym for EVP_EncryptUpdate(). All instances
+ of these calls have also been analysed too and it is believed there are no
+ instances in internal usage where an overflow could occur.
+
+ This issue was reported by Guido Vranken.
+ (CVE-2016-2106)
+ [Matt Caswell]
+
+ *) Prevent ASN.1 BIO excessive memory allocation
+
+ When ASN.1 data is read from a BIO using functions such as d2i_CMS_bio()
+ a short invalid encoding can cause allocation of large amounts of memory
+ potentially consuming excessive resources or exhausting memory.
+
+ Any application parsing untrusted data through d2i BIO functions is
+ affected. The memory based functions such as d2i_X509() are *not* affected.
+ Since the memory based functions are used by the TLS library, TLS
+ applications are not affected.
+
+ This issue was reported by Brian Carpenter.
+ (CVE-2016-2109)
+ [Stephen Henson]
+
+ *) EBCDIC overread
+
+ ASN1 Strings that are over 1024 bytes can cause an overread in applications
+ using the X509_NAME_oneline() function on EBCDIC systems. This could result
+ in arbitrary stack data being returned in the buffer.
+
+ This issue was reported by Guido Vranken.
+ (CVE-2016-2176)
+ [Matt Caswell]
+
+ *) Modify behavior of ALPN to invoke callback after SNI/servername
+ callback, such that updates to the SSL_CTX affect ALPN.
+ [Todd Short]
+
+ *) Remove LOW from the DEFAULT cipher list. This removes singles DES from the
+ default.
+ [Kurt Roeckx]
+
+ *) Only remove the SSLv2 methods with the no-ssl2-method option. When the
+ methods are enabled and ssl2 is disabled the methods return NULL.
+ [Kurt Roeckx]
+
+ 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]
+
projects / openssl.git / blobdiff