Bugzilla – Bug 967026
VUL-0: CVE-2016-0787: libssh2_org: Weakness in diffie-hellman secret key generation
Last modified: 2019-05-22 01:04:15 UTC
bugbot adjusting priority
This is an autogenerated message for OBS integration: This bug (967026) was mentioned in https://build.opensuse.org/request/show/361124 13.2 / libssh2_org
https://www.libssh2.org/adv_20160223.html Truncated Difffie-Hellman secret length Project libssh2 Security Advisory, February 23rd 2016 - Permalink VULNERABILITY During the SSHv2 handshake when libssh2 is to get a suitable value for 'group order' in the Diffle Hellman negotiation, it would pass in number of bytes to a function that expected number of bits. This would result in the library generating numbers using only an 8th the number of random bits than what were intended: 128 or 256 bits instead of 1023 or 2047 Using such drastically reduced amount of random bits for Diffie Hellman weakended the handshake security significantly. There are no known exploits of this flaw at this time. INFO The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2016-0787 to this issue. AFFECTED VERSIONS Affected versions: all versions to and including 1.6.0 Not affected versions: libssh2 >= 1.7.0 libssh2 is used by many applications, but not always advertised as such! THE SOLUTION libssh2 1.7.0 makes sure that there's a convertion done from number of bytes to number of bits when the internal _libssh2_bn_rand function is called. A patch for this problem is available at: https://www.libssh2.org/CVE-2016-0787.patch RECOMMENDATIONS We suggest you take one of the following actions immediately, in order of preference: A - Upgrade to libssh2 1.7.0 B - Apply the patch and rebuild libssh2 TIME LINE It was first reported to the libssh2 project on February 7 2016 by Andreas Schneider. libssh2 1.7.0 was released on February 23rd 2016, coordinated with the publication of this advisory. CREDITS Reported by Andreas Schneider. Thanks a lot!
*** Bug 968174 has been marked as a duplicate of this bug. ***
openSUSE-SU-2016:0639-1: An update that fixes one vulnerability is now available. Category: security (moderate) Bug References: 967026 CVE References: CVE-2016-0787 Sources used: openSUSE 13.2 (src): libssh2_org-1.5.0-9.7.1
SUSE-SU-2016:0718-1: An update that solves one vulnerability and has two fixes is now available. Category: security (moderate) Bug References: 933336,961964,967026 CVE References: CVE-2016-0787 Sources used: SUSE Linux Enterprise Software Development Kit 12-SP1 (src): libssh2_org-1.4.3-16.1 SUSE Linux Enterprise Software Development Kit 12 (src): libssh2_org-1.4.3-16.1 SUSE Linux Enterprise Server 12-SP1 (src): libssh2_org-1.4.3-16.1 SUSE Linux Enterprise Server 12 (src): libssh2_org-1.4.3-16.1 SUSE Linux Enterprise Desktop 12-SP1 (src): libssh2_org-1.4.3-16.1 SUSE Linux Enterprise Desktop 12 (src): libssh2_org-1.4.3-16.1
SUSE-SU-2016:0723-1: An update that solves one vulnerability and has one errata is now available. Category: security (moderate) Bug References: 961964,967026 CVE References: CVE-2016-0787 Sources used: SUSE Linux Enterprise Software Development Kit 11-SP4 (src): libssh2_org-1.2.9-4.2.6.1 SUSE Linux Enterprise Server 11-SP4 (src): libssh2_org-1.2.9-4.2.6.1 SUSE Linux Enterprise Desktop 11-SP4 (src): libssh2_org-1.2.9-4.2.6.1
released