Debian DLA-288-2 : openssh regression update

High Nessus Plugin ID 85278

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VPR Score: 4.2

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: 2.6

Type: local

Agent: unix

Published: 2015/08/10

Updated: 2020/03/12

Dependencies: 12634

Risk Information

Risk Factor: High

VPR Score: 4.2

CVSS v2.0

Base Score: 8.5

Temporal Score: 6.3

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

Temporal Vector: CVSS2#E:U/RL:OF/RC: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 Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2015/09/29

Reference Information

CVE: CVE-2015-5600