CVE-2016-0787

Publication date 13 April 2016

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

The diffie_hellman_sha256 function in kex.c in libssh2 before 1.7.0 improperly truncates secrets to 128 or 256 bits, which makes it easier for man-in-the-middle attackers to decrypt or intercept SSH sessions via unspecified vectors, aka a "bits/bytes confusion bug."

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libssh2	16.10 yakkety	Fixed 1.7.0-1ubuntu0.1
	16.04 LTS xenial	Fixed 1.5.0-2ubuntu0.1
	15.10 wily	Ignored end of life
	14.04 LTS trusty	Fixed 1.4.3-2ubuntu0.1
	12.04 LTS precise	Fixed 1.2.8-2ubuntu0.1

Notes

seth-arnold

Debian noted there may be discussion of incomplete fix

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libssh2	Upstream: ca5222e Upstream: 7934c9c

Severity score breakdown

Parameter	Value
Base score	5.9 · Medium
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	None
Vector	CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N