CVE-2010-3308 Openswan cisco banner option handling vulnerability

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=2010-3308

See also: CVE-2010-3302: Openswan cisco DNS option handling vulnerability

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=2010-3302

Security Alert:

This alert (and any possible updates) is available at the following URL:

http://www.openswan.org/download/CVE-2010-3302/

The Openswan project has discovered two vulnerabilities in the XAUTH

Cisco handling code that could be exploited if openswan connects to a

trusted gateway that has been compromised.

Vulnerable versions: openswan 2.6.26 up to and including openswan 2.6.28

Fixed version : openswan 2.6.29 and above

Vulnerability information:

In very specific circumstances, a buffer overflow and arbitrary shell

commands could be sent to a vulnerable openswan client.

These vulnerabilities can only be triggered when openswan is configured to

connect to a malicious Cisco compatible gateway using XAUTH. It requires

openswan to be configured with *xauthclient=yes and remote_peer_type=cisco,

and requires successful phase1 IKE negotiation. This can only happen to a

vulnerable Openswan client when connecting to a trusted and authenticated

gateway using XAUTH.

An Openswan server receiving VPN connections is not affected by this flaw.

Vulnerability Details:

The field cisco_banner (later renamed to server_banner) were declared as a

fixed length buffer. If a banner is sent with more then 500 characters,

the buffer will overflow. Additionally, the banner was copied

into fmt_common_shell_out() without being sanitized to make it safe

against exploitable characters, such as single quotes('). This was

introduced in git commit id 3615e17463a, on May 19, 2010 and first

released in openswan 2.6.26.

Patch:

For those unable to upgrade to the latest openswan 2.6.29 release, a patch

addressing CVE-2010-3308 and CVE-2010-3302 can be found at:

http://www.openswan.org/download/CVE-2010-3308/

Full release:

The latest openswan release which fixes all known issues can be found at:

http://www.openswan.org/download/openswan-2.6.29.tar.gz

http://www.openswan.org/download/openswan-2.6.29.tar.gz.asc (GPG signature)

Credit:

These vulnerabilities were found by D. Hugh Redelmeier <hugh@mimosa.com>

and Paul Wouters <paul@xelerance.com>

About openswan (http://www.openswan.org/):

Openswan is a free implementation of Internet Protocol Security (IPsec)

and Internet Key Exchange (IKE). IPsec uses strong cryptography to provide

both authentication and encryption services. These services allow you to

build secure tunnels through untrusted networks. Everything passing through

the untrusted network is encrypted by the IPsec gateway machine, and

decrypted by the gateway at the other end of the tunnel. The resulting

tunnel is a virtual private network (VPN).

About Xelerance (http://www.xelerance.com/):

Xelerance is the custodian of the openswan IPsec software and the L2TP

server xl2tpd. These are used in combination to provide Enterprise VPN

solutions. Headquartered in Ottawa, the high-tech capital of Canada,

Xelerance provides products and services to secure the internet. Its

products include DNSX Secure Signer, which won the Best Security Hardware

award at FOSE 2010, and DNSX Secure Resolver.