(RHSA-2013:0827) Important: openswan security update

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. When using Opportunistic
Encryption, Openswan’s pluto IKE daemon requests DNS TXT records to obtain
public RSA keys of itself and its peers.

A buffer overflow flaw was found in Openswan. If Opportunistic Encryption
were enabled (“oe=yes” in “/etc/ipsec.conf”) and an RSA key configured, an
attacker able to cause a system to perform a DNS lookup for an
attacker-controlled domain containing malicious records (such as by sending
an email that triggers a DKIM or SPF DNS record lookup) could cause
Openswan’s pluto IKE daemon to crash or, potentially, execute arbitrary
code with root privileges. With “oe=yes” but no RSA key configured, the
issue can only be triggered by attackers on the local network who can
control the reverse DNS entry of the target system. Opportunistic
Encryption is disabled by default. (CVE-2013-2053)

This issue was discovered by Florian Weimer of the Red Hat Product Security
Team.

All users of openswan are advised to upgrade to these updated packages,
which contain backported patches to correct this issue. After installing
this update, the ipsec service will be restarted automatically.