Debian DLA-288-2 : openssh regression update

high Nessus Plugin ID 85278

Synopsis

The remote Debian host is missing a security update.

Description

In Debian LTS (squeeze), the fix for CVE-2015-5600[1] in openssh 1:5.5p1-6+squeeze7 breaks authentication mechanisms that rely on the keyboard-interactive method. Thanks to Colin Watson for making aware of that.

The patch fixing CVE-2015-5600 introduces the field 'devices_done' to the KbdintAuthctxt struct, but does not initialize the field in the kbdint_alloc() function. On Linux, this ends up filling that field with junk data. The result of this are random login failures when keyboard-interactive authentication is used.

This upload of openssh 1:5.5p1-6+squeeze7 to Debian LTS (squeeze) adds that initialization of the `devices_done` field alongside the existing initialization code.

People relying on keyboard-interactive based authentication mechanisms with OpenSSH on Debian squeeze(-lts) systems are recommended to upgrade OpenSSH to 1:5.5p1-6+squeeze7.

[1] https://lists.debian.org/debian-lts-announce/2015/08/msg00001.html

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Upgrade the affected packages.

See Also

https://lists.debian.org/debian-lts-announce/2015/08/msg00001.html

https://lists.debian.org/debian-lts-announce/2015/09/msg00015.html

https://packages.debian.org/source/squeeze-lts/openssh

Plugin Details

Severity: High

ID: 85278

File Name: debian_DLA-288.nasl

Version: 2.7

Type: local

Agent: unix

Published: 8/10/2015

Updated: 1/11/2021

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.0

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.3

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:openssh-client, p-cpe:/a:debian:debian_linux:openssh-client-udeb, p-cpe:/a:debian:debian_linux:openssh-server, p-cpe:/a:debian:debian_linux:openssh-server-udeb, p-cpe:/a:debian:debian_linux:ssh, p-cpe:/a:debian:debian_linux:ssh-askpass-gnome, p-cpe:/a:debian:debian_linux:ssh-krb5, cpe:/o:debian:debian_linux:6.0

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

Exploit Ease: No known exploits are available

Patch Publication Date: 9/29/2015

Reference Information

CVE: CVE-2015-5600