Information disclosure in openvpn.net OpenVPN

1) Information disclosure

EUVDB-ID: #VU33315

Risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2013-2061

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

The openvpn_decrypt function in crypto.c in OpenVPN 2.3.0 and earlier, when running in UDP mode, allows remote attackers to obtain sensitive information via a timing attack involving an HMAC comparison function that does not run in constant time and a padding oracle attack on the CBC mode cipher.

Mitigation

Install update from vendor's website.

Vulnerable software versions

OpenVPN for Windows: 2.0 _ - 2.3.0

CPE2.3

• cpe:2.3:a:openvpn_net:openvpn:2.0.10:*:*:*:*:*:*:*
• cpe:2.3:a:openvpn_net:openvpn:2.1.28.0:*:*:*:*:*:*:*
• cpe:2.3:a:openvpn_net:openvpn:2.2.2:*:*:*:*:*:*:*
• cpe:2.3:a:openvpn_net:openvpn:2.3.0:*:*:*:*:*:*:*

External links

https://lists.fedoraproject.org/pipermail/package-announce/2013-May/105568.html
https://lists.fedoraproject.org/pipermail/package-announce/2013-May/105609.html
https://lists.opensuse.org/opensuse-updates/2013-11/msg00012.html
https://lists.opensuse.org/opensuse-updates/2013-11/msg00016.html
https://www.mandriva.com/security/advisories?name=MDVSA-2013:167
https://www.openwall.com/lists/oss-security/2013/05/06/6
https://bugs.gentoo.org/show_bug.cgi?id=468756
https://bugzilla.redhat.com/show_bug.cgi?id=960192
https://community.openvpn.net/openvpn/wiki/SecurityAnnouncement-f375aa67cc
https://github.com/OpenVPN/openvpn/commit/11d21349a4e7e38a025849479b36ace7c2eec2ee

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.