Hi Sandesh
The offline dictionary PSK attack isn’t something new (people have known about this since last millennia!). In summary if you have a ‘strong’ PSK you’re safe.. But if you have an active MiTM as described in the paper then they can perform an offline brute force attack against your PSK assuming they have the computing power to find it.. I wrote the following to help explain this.. https://www.linkedin.com/pulse/ike-brute-force-attack-explained-graham-bartlett/ cheers From: Users <users-boun...@lists.strongswan.org> on behalf of Sandesh Sawant <sandesh.saw...@gmail.com> Date: Monday, 3 September 2018 at 10:20 To: "andreas.stef...@strongswan.org" <andreas.stef...@strongswan.org> Cc: "users@lists.strongswan.org" <users@lists.strongswan.org> Subject: Re: [strongSwan] (no subject) Hello Andreas, Thanks for confirming that strongSwan isn't vulnerable to the mentioned attack. However the report claims to have exploits for PSK and RSA signature based authentication also... Quoting from the report abstract: "We exploit a Bleichenbacher oracle in an IKEv1 mode, where RSA encrypted nonces are used for authentication. Using this exploit, we break these RSA encryption based modes, and in addition break RSA signature based authentication in both IKEv1 and IKEv2. Additionally, we describe an offline dictionary attack against the PSK (Pre-Shared Key) based IKE modes, thus covering all available authentication mechanisms of IKE." Can you please confirm that strongSwan isn't vulnerable to the Bleichenbacher attack against IKEv2 signature based auth and offline dictionary attack mentioned for PSK based auth (irrespective of the PSK chosen by the user)? Thanks, Sandesh On Fri, Aug 31, 2018 at 3:50 PM Andreas Steffen <andreas.stef...@strongswan.org> wrote: Hi Sandesh, strongSwan is not vulnerable to the Bleichenbacher oracle attack since we did not implement the RSA encryption authentication variant for IKEv1. Best regards Andreas On 31.08.2018 10:53, Sandesh Sawant wrote: > Hi all, > > I came across below news about a paper enlisting attacks pertaining to > IKE protocol, and want to know whether the latest version of trongSwan > stack is vulnerable to the attacks mentioned in this > paper: > https://www.ei.rub.de/media/nds/veroeffentlichungen/2018/08/13/sec18-felsch.pdf > References: > https://latesthackingnews.com/2018/08/20/ipsec-vpn-connections-broken-using-20-year-old-flaw/ > https://securityaffairs.co/wordpress/75352/hacking/key-reuse-ipsec-attack.html > > Thanks, > Sandesh ====================================================================== Andreas Steffen andreas.stef...@strongswan.org strongSwan - the Open Source VPN Solution! www.strongswan.org Institute for Networked Solutions HSR University of Applied Sciences Rapperswil CH-8640 Rapperswil (Switzerland) ===========================================================[INS-HSR]==
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