FreeBSD Security Advisory FreeBSD-SA-17:12.openssl

============================================================================= FreeBSD-SA-17:12.openssl Security Advisory The FreeBSD Project Topic: OpenSSL multiple vulnerabilities Category: contrib Module: openssl Announced: 2017-12-09 Affects: All supported versions of FreeBSD. Corrected: 2017-12-07 18:04:48 UTC (stable/11, 11.1-STABLE) 2017-12-09 03:44:26 UTC (releng/11.1, 11.1-RELEASE-p6) 2017-12-09 03:41:31 UTC (stable/10, 10.4-STABLE) 2017-12-09 03:45:23 UTC (releng/10.4, 10.4-RELEASE-p5) 2017-12-09 03:45:23 UTC (releng/10.3, 10.3-RELEASE-p26) CVE Name: CVE-2017-3737, CVE-2017-3738 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 for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It is also a full-strength general purpose cryptography library. II. Problem Description Invoking SSL_read()/SSL_write() while in an error state causes data to be 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. [CVE-2017-3737] There is an overflow bug in the x86_64 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. This only affects processors that support the AVX2 but not ADX extensions like Intel Haswell (4th generation). [CVE-2017-3738] This bug only affects FreeBSD 11.x. III. Impact Applications with incorrect error handling may inappropriately pass unencrypted data. [CVE-2017-3737] Mishandling of carry propagation will produce incorrect output, and make it easier for a remote attacker to obtain sensitive private-key information. No EC algorithms are affected and 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 (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. 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. [CVE-2017-3738] 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-17:12/openssl-10.patch # fetch https://security.FreeBSD.org/patches/SA-17:12/openssl-10.patch.asc # gpg --verify openssl-10.patch.asc [FreeBSD 11.x] # fetch https://security.FreeBSD.org/patches/SA-17:12/openssl-11.patch # fetch https://security.FreeBSD.org/patches/SA-17:12/openssl-11.patch.asc # gpg --verify openssl-11.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/10/ r326721 releng/10.3/ r326723 releng/10.4/ r326723 stable/11/ r326663 releng/11.1/ r326722 - ------------------------------------------------------------------------- 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