Full Disclosure mailing list archives
Re: [ GLSA 200512-04 ] Openswan, IPsec-Tools: Vulnerabilities in ISAKMP Protocol implementation
From: Thierry Carrez <koon () gentoo org>
Date: Wed, 14 Dec 2005 13:12:16 +0100
VANHULLEBUS Yvan wrote:
On Tue, Dec 13, 2005 at 09:49:40PM +0100, Paul Wouters wrote:On Mon, 12 Dec 2005, Thierry Carrez wrote: [...]Impact ====== A remote attacker can create a specially crafted packet using 3DES with an invalid key length, resulting in a Denial of Service attack, format string vulnerabilities or buffer overflows.That's a copy and paste from the IPsec proto testsuite. 1) It conflicts with the above comment that this is only a DOS 2) It's incorrect (for openswan)Also incorrect for ipsec-tools AFAIK. The only problem we noticed with protos testsuite was a lack of verification for some payloads existency in aggressive mode.Workaround ========== Avoid using "aggressive mode" in ISAKMP Phase 1, which exchanges information between the sides before there is a secure channel.In fact, you would to both have aggressive mode enabled AND know the PSK. If you have those two enabled, you are vulnerable to a MITM anyway, since any client knowing the PSK can pretend to be the IPsec security gateway.Knowing the PSK is not really needed, as AGGRESSIVE+PSK mode is known to be quite unsecure, and can be bruteforced offline. The "workaround" for ipsec-tools is to upgrade, and is only needed for some people which really have a week configuration and should care about lots of potential problems !
Paul, Yvan, Many thanks for the precisions and sorry for getting it wrong. I'll fix the GLSA text for Impact and Workaround on the Gentoo website asap. -- Thierry Carrez (Koon) Gentoo Linux Security
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Current thread:
- [ GLSA 200512-04 ] Openswan, IPsec-Tools: Vulnerabilities in ISAKMP Protocol implementation Thierry Carrez (Dec 12)
- Re: [ GLSA 200512-04 ] Openswan, IPsec-Tools: Vulnerabilities in ISAK MP Protocol implementation Paul Wouters (Dec 13)
- Re: [ GLSA 200512-04 ] Openswan, IPsec-Tools: Vulnerabilities in ISAK MP Protocol implementation VANHULLEBUS Yvan (Dec 14)
- <Possible follow-ups>
- Re: [ GLSA 200512-04 ] Openswan, IPsec-Tools: Vulnerabilities in ISAKMP Protocol implementation Thierry Carrez (Dec 14)
- Re: [ GLSA 200512-04 ] Openswan, IPsec-Tools: Vulnerabilities in ISAK MP Protocol implementation Paul Wouters (Dec 13)