OpenSSL CHANGES
_______________
- Changes between 1.0.2i and 1.0.2j [xx XXX xxxx]
+ This is a high-level summary of the most important changes.
+ For a full list of changes, see the git commit log; for example,
+ https://github.com/openssl/openssl/commits/ and pick the appropriate
+ release branch.
+
+ Changes between 1.0.2n and 1.0.2o [xx XXX xxxx]
+
+ *)
+
+ Changes between 1.0.2m and 1.0.2n [7 Dec 2017]
+
+ *) Read/write after SSL object in error state
+
+ OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state"
+ mechanism. The intent was that if a fatal error occurred during a handshake
+ then OpenSSL would move into the error state and would immediately fail if
+ you attempted to continue the handshake. This works as designed for the
+ explicit handshake functions (SSL_do_handshake(), SSL_accept() and
+ SSL_connect()), however due to a bug it does not work correctly if
+ SSL_read() or SSL_write() is called directly. In that scenario, if the
+ handshake fails then a fatal error will be returned in the initial function
+ call. If SSL_read()/SSL_write() is subsequently called by the application
+ for the same SSL object then it will succeed and the data is passed without
+ being decrypted/encrypted directly from the SSL/TLS record layer.
+
+ In order to exploit this issue an application bug would have to be present
+ that resulted in a call to SSL_read()/SSL_write() being issued after having
+ already received a fatal error.
+
+ This issue was reported to OpenSSL by David Benjamin (Google).
+ (CVE-2017-3737)
+ [Matt Caswell]
+
+ *) rsaz_1024_mul_avx2 overflow bug on x86_64
+
+ There is an overflow bug in the AVX2 Montgomery multiplication procedure
+ used in exponentiation with 1024-bit moduli. 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 DH1024 are considered just feasible, 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
+ significant. However, for an attack on TLS to be meaningful, the server
+ would have to share the DH1024 private key among multiple clients, which is
+ no longer an option since CVE-2016-0701.
+
+ This only affects processors that support the AVX2 but not ADX extensions
+ like Intel Haswell (4th generation).
+
+ This issue was reported to OpenSSL by David Benjamin (Google). The issue
+ was originally found via the OSS-Fuzz project.
+ (CVE-2017-3738)
+ [Andy Polyakov]
+
+ Changes between 1.0.2l and 1.0.2m [2 Nov 2017]
+
+ *) bn_sqrx8x_internal carry bug 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.
+
+ This only affects processors that support the BMI1, BMI2 and ADX extensions
+ like Intel Broadwell (5th generation) and later or AMD Ryzen.
+
+ This issue was reported to OpenSSL by the OSS-Fuzz project.
+ (CVE-2017-3736)
+ [Andy Polyakov]
+
+ *) Malformed X.509 IPAddressFamily could cause OOB read
+
+ If an X.509 certificate has a malformed IPAddressFamily extension,
+ OpenSSL could do a one-byte buffer overread. The most likely result
+ would be an erroneous display of the certificate in text format.
+
+ This issue was reported to OpenSSL by the OSS-Fuzz project.
+ (CVE-2017-3735)
+ [Rich Salz]
+
+ Changes between 1.0.2k and 1.0.2l [25 May 2017]
+
+ *) Have 'config' recognise 64-bit mingw and choose 'mingw64' as the target
+ platform rather than 'mingw'.
+ [Richard Levitte]
+
+ Changes between 1.0.2j and 1.0.2k [26 Jan 2017]
+
+ *) Truncated packet could crash via OOB read
+
+ If one side of an SSL/TLS path is running on a 32-bit host and a specific
+ cipher is being used, then a truncated packet can cause that host to
+ perform an out-of-bounds read, usually resulting in a crash.
+
+ This issue was reported to OpenSSL by Robert Święcki of Google.
+ (CVE-2017-3731)
+ [Andy Polyakov]
+
+ *) 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. Note: This issue is very
+ similar to CVE-2015-3193 but must be treated as a separate problem.
+
+ This issue was reported to OpenSSL by the OSS-Fuzz project.
+ (CVE-2017-3732)
+ [Andy Polyakov]
+
+ *) Montgomery multiplication may produce incorrect results
+
+ There is a carry propagating bug in the Broadwell-specific Montgomery
+ multiplication procedure that handles input lengths divisible by, but
+ longer than 256 bits. Analysis suggests that attacks against RSA, DSA
+ and DH private keys are impossible. This is because the subroutine in
+ question is not used in operations with the private key itself and an input
+ of the attacker's direct choice. Otherwise the bug can manifest itself as
+ transient authentication and key negotiation failures or reproducible
+ erroneous outcome of public-key operations with specially crafted input.
+ Among EC algorithms only Brainpool P-512 curves are affected and one
+ presumably can attack ECDH key negotiation. Impact was not analyzed in
+ detail, because pre-requisites for attack are considered unlikely. Namely
+ multiple clients have to choose the curve in question and the server has to
+ share the private key among them, neither of which is default behaviour.
+ Even then only clients that chose the curve will be affected.
+
+ This issue was publicly reported as transient failures and was not
+ initially recognized as a security issue. Thanks to Richard Morgan for
+ providing reproducible case.
+ (CVE-2016-7055)
+ [Andy Polyakov]
+
+ *) OpenSSL now fails if it receives an unrecognised record type in TLS1.0
+ or TLS1.1. Previously this only happened in SSLv3 and TLS1.2. This is to
+ prevent issues where no progress is being made and the peer continually
+ sends unrecognised record types, using up resources processing them.
+ [Matt Caswell]
+
+ Changes between 1.0.2i and 1.0.2j [26 Sep 2016]
*) Missing CRL sanity check