OpenSSL v1.0.1.s Release Notes
Release Date: 2016-05-03 // almost 8 years ago-
- 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 casuse 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