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Es werden Posts vom August, 2018 angezeigt.

Practical Bleichenbacher Attacks on IPsec IKE

We found out that reusing a key pair across different versions and modes of IPsec IKE can lead to cross-protocol authentication bypasses, enabling the impersonation of a victim host or network by attackers. These vulnerabilities existed in implementations by Cisco, Huawei, and others.

This week at the USENIX Security conference, I will present our research paper on IPsec attacks: The Dangers of Key Reuse: Practical Attacks on IPsec IKE written by Martin Grothe, Jörg Schwenk, and me from Ruhr University Bochum as well as Adam Czubak and Marcin Szymanek from the University of Opole [alternative link to the paper]. This blog post is intended for people who like to get a comprehensive summary of our findings rather than to read a long research paper.
IPsec and Internet Key Exchange (IKE) IPsec enables cryptographic protection of IP packets. It is commonly used to build VPNs (Virtual Private Networks). For key establishment, the IKE protocol is used. IKE exists in two versions, each with d…

Practical Dictionary Attack on IPsec IKE

We found out that in contrast to public knowledge, the Pre-Shared Key (PSK) authentication method in main mode of IKEv1 is susceptible to offline dictionary attacks. This requires only a single active Man-in-the-Middle attack. Thus, if low entropy passwords are used as PSKs, this can easily be broken.

Save Your Cloud: Gain Root Access to VMs in OpenNebula 4.6.1

In this post, we show a proof-of-concept attack that gives us root access to a victim's VM in the Cloud Management Platform OpenNebula, which means that we can read and write all its data, install software, etc. The interesting thing about the attack is, that it allows an attacker to bridge the gap between the cloud's high-level web interface and the low-level shell-access to a virtual machine.