-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-16:17.openssl Security Advisory The FreeBSD Project Topic: Multiple OpenSSL vulnerabilities Category: contrib Module: openssl Announced: 2016-05-04 Credits: OpenSSL Project Affects: All supported versions of FreeBSD. Corrected: 2016-05-03 18:54:20 UTC (stable/10, 10.3-STABLE) 2016-05-04 15:25:47 UTC (releng/10.3, 10.3-RELEASE-p2) 2016-05-04 15:26:23 UTC (releng/10.2, 10.2-RELEASE-p16) 2016-05-04 15:27:09 UTC (releng/10.1, 10.1-RELEASE-p33) 2016-05-04 06:53:02 UTC (stable/9, 9.3-STABLE) 2016-05-04 15:27:09 UTC (releng/9.3, 9.3-RELEASE-p41) CVE Name: CVE-2016-2105, CVE-2016-2106, CVE-2016-2107, CVE-2016-2109, CVE-2016-2176 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background FreeBSD includes software from the OpenSSL Project. The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library. II. Problem Description The padding check in AES-NI CBC MAC 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. [CVE-2016-2107] An overflow can occur in the EVP_EncodeUpdate() function which is used for Base64 encoding of binary data. [CVE-2016-2105] An overflow can occur in the EVP_EncryptUpdate() function, however it is believed that there can be no overflows in internal code due to this problem. [CVE-2016-2106] 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. [CVE-2016-2109] ASN1 Strings that are over 1024 bytes can cause an overread in applications using the X509_NAME_oneline() function on EBCDIC systems. [CVE-2016-2176] FreeBSD does not run on any EBCDIC systems and therefore is not affected. III. Impact 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. [CVE-2016-2107] If an attacker is able to supply very large amounts of input data then a length check can overflow resulting in a heap corruption. [CVE-2016-2105] Any application parsing untrusted data through d2i BIO functions are vulnerable to memory exhaustion attack. [CVE-2016-2109] TLS applications are not affected. IV. Workaround No workaround is available. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Restart all daemons that use the library, or reboot the system. 2) To update your vulnerable system via a binary patch: Systems running a RELEASE version of FreeBSD on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install Restart all daemons that use the library, or reboot the system. 3) To update your vulnerable system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 10.x] # fetch https://security.FreeBSD.org/patches/SA-16:17/openssl-10.patch # fetch https://security.FreeBSD.org/patches/SA-16:17/openssl-10.patch.asc # gpg --verify openssl-10.patch.asc [FreeBSD 9.3] # fetch https://security.FreeBSD.org/patches/SA-16:17/openssl-9.patc # fetch https://security.FreeBSD.org/patches/SA-16:17/openssl-9.patch.asc # gpg --verify openssl-9.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in . Restart all daemons that use the library, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/9/ r299053 releng/9.3/ r299068 stable/10/ r298999 releng/10.1/ r299068 releng/10.2/ r299067 releng/10.3/ r299066 - ------------------------------------------------------------------------- To see which files were modified by a particular revision, run the following command, replacing NNNNNN with the revision number, on a machine with Subversion installed: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJXKjuIAAoJEO1n7NZdz2rneZoP/jqsWr9q5MkCel2aZzfmSVhU 8CjzPwm3t48ibZqrkolAak4dbjJGhidUM/S83BvIcCdtKWyoG8D0fzemB7bBIP2L fqvd1314vuy82CgZlAyJIqzokckUPfyHhTAz9FPZW46f8A+s8znzJcaaD81tt1Xe qg9JZ61e2DZJ2NdZSJSjOpBl55gZqQq3tIwGYw027GKjiflJSvOG1n/531R4rppI x0IZpLor7XBWuiC44hPc4yasC4khWzmdaRpqcUoWVEex8g6Il6xByS2o4AgX7kE/ NBZ0mj4IMYZNQW4VUYbnkmLtWXJYYScboBKh4FRljNCG/t5u/YoSfOY8SbS9LT9K KVj56C6tQRq+/frKbPt26HbqqRTFNVn3FKxJWNQ9CLzsebobXPUYATTN2NVC8gkj S0A/lT2xnvA2YqB9HfmHOvlHS2LDv8SivJWNK4dCPOwhVm624H4qH/N+VFcwU7zc ue+BPvDYU/czsyoJDdQoWxTdkreaOY6eLAWkYAh9dEDIkZSOxgsZR7C4th6THXMu ybIy544elc3bf9vS4tGR552Wi9VntE0B1/LJ2la8l+MnYE6qZL1hbAYpvNyuPWVP EDPjOc4inaMpV62fuL1UrKH1g1HMmFUnoWhC70iS+cuLeXWFdvwBFyL420Ixkd5H zvcsfJCrazlcZ6j83Qfd =PGTh -----END PGP SIGNATURE-----