Cisco Patches IOS in Response to Boffins' IKE-Busting Breakthrough

Switchzilla issues update for authentication bypass flaw
Cisco has pushed out an update for its internetwork operating system (IOS) and IOS XE firmware in advance of a Usenix presentation on circumventing cryptographic key protocol.
The networking behemoth is advising all customers running hardware that uses IOS and IOS XE to get the updates that address CVE-2018-0131, a security bypass vulnerability stemming from a weakness in the Internet Key Exchange (IKEv1) protocol.
Researchers Dennis Felsch, Martin Grothe, Jörg Schwenk, Adam Czubak, and Marcin Szymanek from Ruhr-University Bochum and University of Opole found [PDF] that an attacker could contact a device with ciphertext requests that, under the right circumstances, could cause the target device to disclose the encrypted nonces (single-use numbers for encryption keys) and potentially lead to the keys being broken.
The group, who plan to share their findings later this week at the conference, wrote that "reusing a key pair across different versions and modes of IKE can lead to cross-protocol authentication bypasses, enabling the impersonation of a victim host or network by attackers."
The attack would potentially be carried out either by eavesdropping on IP sessions or by performing a man-in-the-middle compromise and injecting code into packets.
The researchers say that, by deliberately sending bad cipher requests to the vulnerable machines, they could receive enough data to create a type of Bleichenbacher's Oracle [PDF] attack on the keys. This would, given enough time, would potentially allow the attacker to decrypt shared keys and get around encryption protections.
The researchers noted that they have already disclosed their findings to Cisco and other vendors impacted by the issue, and all are believed to have issued patches for vulnerable products prior to the publication of the paper.
Cisco says in its advisory that, short of moving off of IKEv1, there are no workarounds for the vulnerability. Switchzilla is advising anyone using an IOS or IOS XE device that is configured with the 'authentication rsa-encr' option turned on to update their firmware and make sure they have the patched IOS version.
The latest available version will vary based on device and model, but in general IOS versions 15.5(3)M7.2 and later will be protected.
Source: theregister

Latest Jobs
-
- Identity Channel Partner Manager | London
- London
- N/A
-
Identity Channel Partner Manager | London Location: South East UK (commutable to London) We are working with a Cyber Security business who are looking for a Channel Partner Manager to drive and grow relationships across their identity ecosystem. Prior experience working within VARs, distributors, vendors or resellers in the identity space is essential. You must have experience working with technologies such as CyberArk, Sailpoint, Okta etc Responsibilities will include, but not be limited to: Build, maintain and develop strong relationships with channel partners. Work closely with partner sales teams to support growth drive sales opportunities. Identify and onboard new partners while strengthening existing partnerships. Act as the key point of contact for all channel-related activity. If you are an experienced channel professional, with experience in the Identity space and are ready for your next challenge, apply today.
-
- Microsoft Security Operations Analyst | Bracknell | SC Clearable | SC-200
- Reading
- N/A
-
Senior SOC Analyst Level 2 / 3. Microsoft Security stack | SC Clearable Location: Hybrid remote | Berkshire SC-200 Senior SOC Analyst Level 2 / 3 to join a specialist Managed Security Services business. You will be responsible for advanced threat hunting / triage, incident response etc with a strong focus on the Microsoft Security Stack. Key Responsibilities: Lead and resolve complex security incidents / escalations Conduct advanced threat hunting using the Microsoft Security Stack. Build, optimise and maintain workbooks, rules, analytics etc. Correlate data across Microsoft 365 Defender, Azure Defender and Sentinel. Perform root cause analysis and post-incident reporting. Aid in mentoring and upskilling Level 1 and 2 SOC analysts. Required Skills & Experience: The ability to achieve UK Security Clearance (SC) - existing clearance ideal. (Sorry no visa applications) Must have current experience working with a SOC environment Key experience must also include, but not be limited to Development and tuning of custom analytic rules. Workbook creation and dashboarding. Automation using Playbooks and SOAR integration. Kusto Query Language (KQL).