OpenSSH >= 2.3.0 AllowTcpForwarding Port Bouncing

Medium Nessus Plugin ID 17744

Synopsis

The remote SSH server may permit anonymous port bouncing.

Description

According to its banner, the remote host is running OpenSSH, version 2.3.0 or later. Such versions of OpenSSH allow forwarding TCP connections. If the OpenSSH server is configured to allow anonymous connections (e.g. AnonCVS), remote, unauthenticated users could use the host as a proxy.

Solution

Disallow anonymous users, set AllowTcpForwarding to 'no', or use the Match directive to restrict anonymous users.

See Also

http://marc.info/?l=bugtraq&m=109413637313484&w=2

http://www.nessus.org/u?2c86d008

Plugin Details

Severity: Medium

ID: 17744

File Name: openssh_tcp_forwarding.nasl

Version: 1.3

Type: remote

Family: Misc.

Published: 2011/12/01

Modified: 2018/08/13

Dependencies: 10267

Risk Information

Risk Factor: Medium

CVSSv2

Base Score: 6.4

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

Vulnerability Information

CPE: cpe:/a:openbsd:openssh

Vulnerability Publication Date: 2004/08/21

Reference Information

CVE: CVE-2004-1653