Fedora 8 : openvpn-2.1-0.29.rc15.fc8 (2008-10499)

This script is Copyright (C) 2008-2015 Tenable Network Security, Inc.

Synopsis :

The remote Fedora host is missing a security update.

Description :

2008.11.19 -- Version 2.1_rc15 * Fixed issue introduced in 2.1_rc14
that may cause a segfault when a --plugin module is used. * Added
server-side --opt-verify option: clients that connect with options
that are incompatible with those of the server will be disconnected
(without this option, incompatible clients would trigger a warning
message in the server log but would not be disconnected). * Added
--tcp-nodelay option: Macro that sets TCP_NODELAY socket flag on the
server as well as pushes it to connecting clients. * Minor options
check fix: --no-name-remapping is a server-only option and should
therefore generate an error when used on the client. * Added --prng
option to control PRNG (pseudo-random number generator) parameters. In
previous OpenVPN versions, the PRNG was hard-coded to use the SHA1
hash. Now any OpenSSL hash may be used. This is part of an effort to
remove hard-coded references to a specific cipher or cryptographic
hash algorithm. * Cleaned up man page synopsis. 2008.11.16 -- Version

- Added AC_GNU_SOURCE to configure.ac to enable struct
ucred, with the goal of fixing a build issue on Fedora 9
that was introduced in 2.1_rc13. * Added additional
method parameter to --script-security to preserve
backward compatibility with system() call semantics used
in OpenVPN 2.1_rc8 and earlier. To preserve backward
compatibility use: script-security 3 system * Added
additional warning messages about --script-security 2 or
higher being required to execute user-defined scripts or
executables. * Windows build system changes: Modified
Windows domake-win build system to write all openvpn.nsi
input files to gen, so that gen can be disconnected from
the rest of the source tree and makensis openvpn.nsi
will still function correctly. Added additional
SAMPCONF_(CA|CRT|KEY) macros to settings.in (commented
out by default). Added optional files SAMPCONF_CONF2
(second sample configuration file) and SAMPCONF_DH
(Diffie- Helman parameters) to Windows build system, and
may be defined in settings.in. * Extended Management
Interface 'bytecount' command to work when OpenVPN is
running as a server. Documented Management Interface
'bytecount' command in management/management-notes.txt.
* Fixed informational message in ssl.c to properly
indicate deferred authentication.

- Added server-side --auth-user-pass-optional directive,
to allow connections by clients that do not specify a
username/password, when a user-defined authentication
script/module is in place (via --auth-user-pass-verify,
--management-client-auth, or a plugin module). * Changes
to easy- rsa/2.0/pkitool and related openssl.cnf:
Calling scripts can set the KEY_NAME environmental
variable to set the 'name' X509 subject field in
generated certificates. Modified pkitool to allow
flexibility in separating the Common Name convention
from the cert/key filename convention. For example:
KEY_CN='James's Laptop' KEY_NAME='james' ./pkitool james
will create a client certificate/key pair of
james.crt/james.key having a Common Name of 'James's
Laptop' and a Name of 'james'. * Added
--no-name-remapping option to allow Common Name, X509
Subject, and username strings to include any printable
character including space, but excluding control
characters such as tab, newline, and carriage-return
(this is important for compatibility with external
authentication systems). As a related change, added
--status-version 3 format (and 'status 3' in the
management interface) which uses the version 2 format
except that tabs are used as delimiters instead of
commas so that there is no ambiguity when parsing a
Common Name that contains a comma. Also, save X509
Subject fields to environment, using the naming
convention: X509_{cert_depth}_{name}={value} This is to
avoid ambiguities when parsing out the X509 subject
string since '/' characters could potentially be used in
the common name. * Fixed some ifconfig-pool issues that
precluded it from being combined with --server
directive. Now, for example, we can configure thusly:
server nopool ifconfig-pool to have ifconfig-pool
manage only a subset of the VPN subnet. * Added config
file option 'setenv FORWARD_COMPATIBLE 1' to relax
config file syntax checking to allow directives for
future OpenVPN versions to be ignored. 2008.10.07 --
Version 2.1_rc13 * Bundled OpenSSL 0.9.8i with Windows
installer. * Management interface can now listen on a
unix domain socket, for example: management /tmp/openvpn
unix Also added management-client-user and
management-client-group directives to control which
processes are allowed to connect to the socket. *
Copyright change to OpenVPN Technologies, Inc.
2008.09.23 -- Version 2.1_rc12 * Patched Makefile.am so
that the new t_cltsrv-down.sh script becomes part of the
tarball (Matthias Andree). * Fixed --lladdr bug
introduced in 2.1-rc9 where input validation code was
incorrectly expecting the lladdr parameter to be an IP
address when it is actually a MAC address (HoverHell).
2008.09.14 -- Version 2.1_rc11 * Fixed a bug that can
cause SSL/TLS negotiations in UDP mode to fail if UDP
packets are dropped. 2008.09.10 -- Version 2.1_rc10

- Added '--server-bridge' (without parameters) to enable
DHCP proxy mode: Configure server mode for ethernet
bridging using a DHCP-proxy, where clients talk to the
OpenVPN server-side DHCP server to receive their IP
address allocation and DNS server addresses. * Added
'--route-gateway dhcp', to enable the extraction of the
gateway address from a DHCP negotiation with the OpenVPN
server-side LAN. * Fixed minor issue with
--redirect-gateway bypass- dhcp or bypass-dns on
Windows. If the bypass IP address is or, ignore it. * Warn when ethernet
bridging that the IP address of the bridge adapter is
probably not the same address that the LAN adapter was
set to previously. * When running as a server, warn if
the LAN network address is the all-popular
192.168.[0|1].x, since this condition commonly leads to
subnet conflicts down the road. * Primarily on the
client, check for subnet conflicts between the local LAN
and the VPN subnet.

- Added a 'netmask' parameter to get_default_gateway, to
return the netmask of the adapter containing the default
gateway. Only implemented on Windows so far. Other
platforms will return Currently the
netmask information is only used to warn about subnet
conflicts. * Minor fix to cryptoapi.c to not compile
itself unless USE_CRYPTO and USE_SSL flags are enabled
(Alon Bar-Lev). * Updated openvpn/t_cltsrv.sh (used by
'make check') to conform to new --script-security rules.
Also adds retrying if the addresses are in use (Matthias
Andree). * Fixed build issue with ./configure
--disable-socks --disable-http. * Fixed separate compile
errors in options.c and ntlm.c that occur on strict C
compilers (such as old versions of gcc) that require
that C variable declarations occur at the start of a {}
block, not in the middle. * Workaround bug in OpenSSL
0.9.6b ASN1_STRING_to_UTF8, which the new implementation
of extract_x509_field_ssl depends on. * LZO compression
buffer overflow errors will now invalidate the packet
rather than trigger a fatal assertion. * Fixed minor
compile issue in ntlm.c (mid-block declaration). * Added
--allow-pull-fqdn option which allows client to pull DNS
names from server (rather than only IP address) for
--ifconfig, --route, and --route-gateway. OpenVPN
versions 2.1_rc7 and earlier allowed DNS names for these
options to be pulled and translated to IP addresses by
default. Now --allow-pull-fqdn will be explicitly
required on the client to enable DNS-name-to-IP-address
translation of pulled options.

- 2.1_rc8 and earlier did implicit shell expansion on
script arguments since all scripts were called by
system(). The security hardening changes made to 2.1_rc9
no longer use system(), but rather use the safer execve
or CreateProcess system calls. The security hardening
also introduced a backward incompatibility with 2.1_rc8
and earlier in that script parameters were no longer
shell-expanded, so for example: client-connect 'docc
CLIENT-CONNECT' would fail to work because execve would
try to execute a script called 'docc CLIENT-CONNECT'
instead of 'docc' with 'CLIENT-CONNECT' as the first
argument. This patch fixes the issue, bringing the
script argument semantics back to pre 2.1_rc9 behavior
in order to preserve backward compatibility while still
using execve or CreateProcess to execute the
script/executable. * Modified ip_or_dns_addr_safe, which
validates pulled DNS names, to more closely conform to
RFC 3696: (1) DNS name length must not exceed 255
characters (2) DNS name characters must be limited to
alphanumeric, dash ('-'), and dot ('.') * Fixed bug in
intra-session TLS key rollover that was introduced with
deferred authentication features in 2.1_rc8. 2008.07.31
-- Version 2.1_rc9 * Security Fix -- affects non-
Windows OpenVPN clients running OpenVPN 2.1-beta14
through 2.1-rc8 (OpenVPN 2.0.x clients are NOT
vulnerable nor are any versions of the OpenVPN server
vulnerable). An OpenVPN client connecting to a malicious
or compromised server could potentially receive an
'lladdr' or 'iproute' configuration directive from the
server which could cause arbitrary code execution on the
client. A successful attack requires that (a) the client
has agreed to allow the server to push configuration
directives to it by including 'pull' or the macro
'client' in its configuration file, (b) the client
successfully authenticates the server, (c) the server is
malicious or has been compromised and is under the
control of the attacker, and (d) the client is running a
non-Windows OS. Credit: David Wagner. * Miscellaneous
defensive programming changes to multiple areas of the
code. In particular, use of the system() call for
calling executables such as ifconfig, route, and
user-defined scripts has been completely revamped in
favor of execve() on unix and CreateProcess() on

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

See also :


Solution :

Update the affected openvpn package.

Risk factor :

Medium / CVSS Base Score : 5.1
CVSS Temporal Score : 4.4
Public Exploit Available : false

Family: Fedora Local Security Checks

Nessus Plugin ID: 35226 (fedora_2008-10499.nasl)

Bugtraq ID: 30532


Ready to Amp Up Your Nessus Experience?

Get Nessus Professional to scan unlimited IPs, run compliance checks & more

Buy Nessus Professional Now