Debian DSA-3626-1 : openssh - security update

Medium Nessus Plugin ID 92526

Synopsis

The remote Debian host is missing a security-related update.

Description

Eddie Harari reported that the OpenSSH SSH daemon allows user enumeration through timing differences when trying to authenticate users. When sshd tries to authenticate a non-existing user, it will pick up a fixed fake password structure with a hash based on the Blowfish algorithm. If real users passwords are hashed using SHA256/SHA512, then a remote attacker can take advantage of this flaw by sending large passwords, receiving shorter response times from the server for non-existing users.

Solution

Upgrade the openssh packages.

For the stable distribution (jessie), this problem has been fixed in version 1:6.7p1-5+deb8u3.

See Also

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=831902

https://packages.debian.org/source/jessie/openssh

https://www.debian.org/security/2016/dsa-3626

Plugin Details

Severity: Medium

ID: 92526

File Name: debian_DSA-3626.nasl

Version: 2.7

Type: local

Agent: unix

Published: 2016/07/25

Updated: 2018/11/10

Dependencies: 12634

Risk Information

Risk Factor: Medium

CVSS v2.0

Base Score: 4.3

Temporal Score: 3.4

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N

Temporal Vector: CVSS2#E:POC/RL:OF/RC:C

CVSS v3.0

Base Score: 5.9

Temporal Score: 5.3

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:openssh, cpe:/o:debian:debian_linux:8.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2016/07/24

Reference Information

CVE: CVE-2016-6210

DSA: 3626