Buffer overflow in the atodn function in Openswan before 2.6.39, when Opportunistic Encryption is enabled and an RSA key is being used, allows remote attackers to cause a denial of service (pluto IKE daemon crash) and possibly execute arbitrary code via crafted DNS TXT records. NOTE: this might be the same vulnerability as CVE-2013-2052 and CVE-2013-2054.

Two vulnerabilities were fixed in Openswan, an IKE/IPsec implementation for Linux.

  - CVE-2013-2053     During an audit of Libreswan (with which Openswan shares     some code), Florian Weimer found a remote buffer     overflow in the atodn() function. This vulnerability can     be triggered when Opportunistic Encryption (OE) is     enabled and an attacker controls the PTR record of a     peer IP address. Authentication is not needed to trigger     the vulnerability.

  - CVE-2013-6466     Iustina Melinte found a vulnerability in Libreswan which     also applies to the Openswan code. By carefully crafting     IKEv2 packets, an attacker can make the pluto daemon     dereference non-received IKEv2 payload, leading to the     daemon crash. Authentication is not needed to trigger     the vulnerability.

Patches were originally written to fix the vulnerabilities in Libreswan, and have been ported to Openswan by Paul Wouters from the Libreswan Project.

Since the Openswan package is not maintained anymore in the Debian distribution and is not available in testing and unstable suites, it is recommended for IKE/IPsec users to switch to a supported implementation like strongSwan.

The remote host is affected by the vulnerability described in GLSA-201401-09 (Openswan: User-assisted execution of arbitrary code)

    A buffer overflow flaw has been discovered in Openswan when using       Opportunistic Encryption.
  Impact :

    A remote attacker could send a specially crafted DNS TXT record,       possibly resulting in execution of arbitrary code with the privileges of       the process or a Denial of Service condition.
  Workaround :

    There is no known workaround at this time.

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)

The remote Oracle Linux 5 / 6 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2013-0827 advisory.

    [2.6.32-20]     Resolves: #960234 - CVE-2013-2053

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

This openswan update fixes a remote buffer overflow issue. (bnc#824316 / CVE-2013-2053)

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)

After installing this update, the ipsec service will be restarted automatically.

Updated openswan packages that fix one security issue are now available for Red Hat Enterprise Linux 5 and 6.

The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

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.

ID	Name	Product	Family	Severity
73293	Debian DSA-2893-1 : openswan - security update	Nessus	Debian Local Security Checks	medium
72017	GLSA-201401-09 : Openswan: User-assisted execution of arbitrary code	Nessus	Gentoo Local Security Checks	medium
69750	Amazon Linux AMI : openswan (ALAS-2013-192)	Nessus	Amazon Linux Local Security Checks	medium
68822	Oracle Linux 5 / 6 : openswan (ELSA-2013-0827)	Nessus	Oracle Linux Local Security Checks	critical
67199	SuSE 10 Security Update : openswan (ZYPP Patch Number 8627)	Nessus	SuSE Local Security Checks	medium
67197	SuSE 11.2 Security Update : openswan (SAT Patch Number 7925)	Nessus	SuSE Local Security Checks	medium
66462	Scientific Linux Security Update : openswan on SL5.x, SL6.x i386/x86_64 (20130515)	Nessus	Scientific Linux Local Security Checks	medium
66459	RHEL 5 / 6 : openswan (RHSA-2013:0827)	Nessus	Red Hat Local Security Checks	medium
66451	CentOS 5 / 6 : openswan (CESA-2013:0827)	Nessus	CentOS Local Security Checks	medium

Detections

Analytics

CVE-2013-2053

critical

Tenable Plugins

medium

medium

medium

critical

medium

medium

medium

medium

medium