Changes between 1.0.2 and 1.0.2a [xx XXX xxxx]
+ *) ClientHello sigalgs DoS fix
+
+ If a client connects to an OpenSSL 1.0.2 server and renegotiates with an
+ invalid signature algorithms extension a NULL pointer dereference will
+ occur. This can be exploited in a DoS attack against the server.
+
+ This issue was was reported to OpenSSL by David Ramos of Stanford
+ University.
+ (CVE-2015-0291)
+ [Stephen Henson and Matt Caswell]
+
+ *) Multiblock corrupted pointer fix
+
+ OpenSSL 1.0.2 introduced the "multiblock" performance improvement. This
+ feature only applies on 64 bit x86 architecture platforms that support AES
+ NI instructions. A defect in the implementation of "multiblock" can cause
+ OpenSSL's internal write buffer to become incorrectly set to NULL when
+ using non-blocking IO. Typically, when the user application is using a
+ socket BIO for writing, this will only result in a failed connection.
+ However if some other BIO is used then it is likely that a segmentation
+ fault will be triggered, thus enabling a potential DoS attack.
+
+ This issue was reported to OpenSSL by Daniel Danner and Rainer Mueller.
+ (CVE-2015-0290)
+ [Matt Caswell]
+
+ *) Segmentation fault in DTLSv1_listen fix
+
+ The DTLSv1_listen function is intended to be stateless and processes the
+ initial ClientHello from many peers. It is common for user code to loop
+ over the call to DTLSv1_listen until a valid ClientHello is received with
+ an associated cookie. A defect in the implementation of DTLSv1_listen means
+ that state is preserved in the SSL object from one invocation to the next
+ that can lead to a segmentation fault. Errors processing the initial
+ ClientHello can trigger this scenario. An example of such an error could be
+ that a DTLS1.0 only client is attempting to connect to a DTLS1.2 only
+ server.
+
+ This issue was reported to OpenSSL by Per Allansson.
+ (CVE-2015-0207)
+ [Matt Caswell]
+
+ *) Segmentation fault in ASN1_TYPE_cmp fix
+
+ The function ASN1_TYPE_cmp will crash with an invalid read if an attempt is
+ made to compare ASN.1 boolean types. Since ASN1_TYPE_cmp is used to check
+ certificate signature algorithm consistency 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.
+ (CVE-2015-0286)
+ [Stephen Henson]
+
+ *) Segmentation fault for invalid PSS parameters fix
+
+ The signature verification routines will crash with a NULL pointer
+ dereference if presented with an ASN.1 signature using the RSA PSS
+ algorithm and invalid parameters. 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 was reported to OpenSSL by Brian Carpenter.
+ (CVE-2015-0208)
+ [Stephen Henson]
+
+ *) ASN.1 structure reuse memory corruption fix
+
+ Reusing a structure in ASN.1 parsing may allow an attacker to cause
+ memory corruption via an invalid write. Such reuse is and has been
+ strongly discouraged and is believed to be rare.
+
+ Applications that parse structures containing CHOICE or ANY DEFINED BY
+ components may be affected. Certificate parsing (d2i_X509 and related
+ functions) are however not affected. OpenSSL clients and servers are
+ not affected.
+ (CVE-2015-0287)
+ [Stephen Henson]
+
+ *) PKCS7 NULL pointer dereferences fix
+
+ The PKCS#7 parsing code does not handle missing outer ContentInfo
+ correctly. An attacker can craft malformed ASN.1-encoded PKCS#7 blobs with
+ missing content and trigger a NULL pointer dereference on parsing.
+
+ Applications that verify PKCS#7 signatures, decrypt PKCS#7 data or
+ otherwise parse PKCS#7 structures from untrusted sources are
+ affected. OpenSSL clients and servers are not affected.
+
+ This issue was reported to OpenSSL by Michal Zalewski (Google).
+ (CVE-2015-0289)
+ [Emilia Käsper]
+
+ *) DoS via reachable assert in SSLv2 servers fix
+
+ A malicious client can trigger an OPENSSL_assert (i.e., an abort) in
+ servers that both support SSLv2 and enable export cipher suites by sending
+ a specially crafted SSLv2 CLIENT-MASTER-KEY message.
+
+ This issue was discovered by Sean Burford (Google) and Emilia Käsper
+ (OpenSSL development team).
+ (CVE-2015-0293)
+ [Emilia Käsper]
+
+ *) Empty CKE with client auth and DHE fix
+
+ If client auth is used then a server can seg fault in the event of a DHE
+ ciphersuite being selected and a zero length ClientKeyExchange message
+ being sent by the client. This could be exploited in a DoS attack.
+ (CVE-2015-1787)
+ [Matt Caswell]
+
+ *) Handshake with unseeded PRNG fix
+
+ Under certain conditions an OpenSSL 1.0.2 client can complete a handshake
+ with an unseeded PRNG. The conditions are:
+ - The client is on a platform where the PRNG has not been seeded
+ automatically, and the user has not seeded manually
+ - A protocol specific client method version has been used (i.e. not
+ SSL_client_methodv23)
+ - A ciphersuite is used that does not require additional random data from
+ the PRNG beyond the initial ClientHello client random (e.g. PSK-RC4-SHA).
+
+ If the handshake succeeds then the client random that has been used will
+ have been generated from a PRNG with insufficient entropy and therefore the
+ output may be predictable.
+
+ For example using the following command with an unseeded openssl will
+ succeed on an unpatched platform:
+
+ openssl s_client -psk 1a2b3c4d -tls1_2 -cipher PSK-RC4-SHA
+ (CVE-2015-0285)
+ [Matt Caswell]
+
+ *) Use After Free following d2i_ECPrivatekey error fix
+
+ A malformed EC private key file consumed via the d2i_ECPrivateKey function
+ could cause a use after free condition. This, in turn, could cause a double
+ free in several private key parsing functions (such as d2i_PrivateKey
+ or EVP_PKCS82PKEY) and could lead to a DoS attack or memory corruption
+ for applications that receive EC private keys from untrusted
+ sources. This scenario is considered rare.
+
+ This issue was discovered by the BoringSSL project and fixed in their
+ commit 517073cd4b.
+ (CVE-2015-0209)
+ [Matt Caswell]
+
+ *) X509_to_X509_REQ NULL pointer deref fix
+
+ The function X509_to_X509_REQ will crash with a NULL pointer dereference if
+ the certificate key is invalid. This function is rarely used in practice.
+
+ This issue was discovered by Brian Carpenter.
+ (CVE-2015-0288)
+ [Stephen Henson]
+
*) Removed the export ciphers from the DEFAULT ciphers
[Kurt Roeckx]