To prevent malicious Wi-Fi clients from attacking other clients on the same network, vendors have introduced client isolation, a combination of mechanisms that block direct communication between clients. However, client isolation is not a standardized feature, making its security guarantees unclear. In this paper, we undertake a structured security analysis of Wi-Fi client isolation and uncover new classes of attacks that bypass this protection. We identify several root causes behind these weaknesses. First, Wi-Fi keys that protect broadcast frames are improperly managed and can be abused to bypass client isolation. Second, isolation is often only enforced at the MAC or IP layer, but not both. Third, weak synchronization of a client’s identity across the network stack allows one to bypass Wi-Fi client isolation at the network layer instead, enabling the interception of uplink and downlink traffic of other clients as well as internal backend devices. Every tested router and network was vulnerable to at least one attack. More broadly, the lack of standardization leads to inconsistent, ad hoc, and often incomplete implementations of isolation across vendors. Building on these insights, we design and evaluate end-toend attacks that enable full machine-in-the-middle capabilities in modern Wi-Fi networks. Although client isolation effectively mitigates legacy attacks like ARP spoofing, which has long been considered the only universal method for achieving machinein-the-middle positioning in local area networks, our attack introduces a general and practical alternative that restores this capability, even in the presence of client isolation.

For more information, see:  
https://www.ndss-symposium.org/ndss-paper/airsnitch-demystifying-and-breaking-client-isolation-in-wi-fi-networks/

We design DiStefano: an efficient, maliciously-secure framework for generating private commitments over TLS-encrypted web traffic, for verification by a designated third-party. DiStefano provides many improvements over previous TLS commitment systems, including: a modular protocol specific to TLS 1.3, support for arbitrary verifiable claims over encrypted data, client browsing history privacy amongst pre-approved TLS servers, and various optimisations to ensure fast online performance of the TLS 1.3 session. We build a permissive open-source implementation of DiStefano integrated into the BoringSSL cryptographic library (used by Chromium-based Internet browsers). We show that DiStefano is practical in both LAN and WAN settings for committing to facts in arbitrary TLS traffic, requiring < 1 s and ≤ 80 KiB to execute the complete online phase of the protocol.

Modern productivity apps, automation platforms, and AI agents orchestrate across external tools through cloudbased “connectors”. To obtain authorized access to connector accounts, these applications rely extensively on the OAuth 2.0 protocol. However, tracking authorization context across web origins and user-agents, while maintaining the binding to the applications' own user identities (i.e., a secure Account Linking process), pushes OAuth beyond its original client-server model assumptions. The rise of the OAuth-as-a-Service (OaaS) paradigm further complicates trust boundaries in OAuth. In this paper, we present the first comprehensive study of OAuth-based account (mis)linking in connector ecosystems. By systematizing real-world account linking architectural patterns, we show how “OAuth connections”, commonly introduced to manage account linking, can inadvertently break session integrity and security boundaries in OAuth. This enables multiple forms of connector account takeovers. We develop OASIS (OAuth Session Integrity Scanner), an analysis framework that identifies account linking implementations and detects novel Cross-user OAuth session fixation (COSF) vulnerabilities in mobile apps. Our empirical analysis discovers 40 vendors susceptible to COSF and identifies additional Cross-tenant confused deputy threats in 8 OaaS providers. We propose practical countermeasures that have since been adopted by major vendors such as Amazon Bedrock AgentCore. We lead ongoing discussions and standardization efforts to update OAuth security best practices in the IETF.

For more information, see:
paper: https://ieeexplore.ieee.org/abstract/document/11573408/
related talk at IETF: https://youtu.be/C72Saxe03tk?t=2700

Kubernetes has emerged as the de facto standard for container orchestration. Unfortunately, its increasing popularity has also made it an attractive target for malicious actors. Despite extensive research on securing Kubernetes, little attention has been paid to the impact of network configuration on the security of application deployments. This paper addresses this gap by conducting a comprehensive analysis of network misconfigurations in a Kubernetes cluster with specific reference to lateral movement. Accordingly, we carried out an extensive evaluation of 287 open-source applications belonging to six different organizations, ranging from IT companies and public entities to non-profits. As a result, we identified 634 misconfigurations, well beyond what could be found by solutions in the state of the art. We responsibly disclosed our findings to the concerned organizations and engaged in a discussion to assess their severity. As of now, misconfigurations affecting more than thirty applications have been fixed with the mitigations we proposed.

Multiple Perspective Issuance Corroboration (MPIC) is a defense that strengthens the Domain Control Validation protocol run by Certificate Authorities (CAs) against network attacks (e.g., routing hijacks). Despite its recent adoption as a requirement by the CA/Browser Forum, the quantitative security benefits of MPIC in light of real-world routing behaviors are not well understood. We seek to address this challenge by creating a framework to test the effects of real-world BGP hijacks on millions of potential MPIC perspective deployments. Our framework launches around 1500 ethical BGP hijacks on IP prefixes we own and analyzes how potential MPIC perspectives route under these attacks. We consider over 100 global MPIC perspective locations spread across 3 major cloud providers. We find that optimal MPIC deployments can prevent certificate misissuance for over 87% of our evaluated real-world BGP hijacks. We further show that different routing behaviors by cloud providers, such as cold potato routing, have a substantial effect on MPIC's ability to limit the impact of BGP attacks. Finally, our framework computes optimized sets of MPIC perspective locations for CAs to use given their preference of cloud provider and perspective count. Our recommendations have already impacted the MPIC deployment at Google Trust Services, and have been adopted as the default recommendation by the Open MPIC project.

For more information, see:
paper: https://dl.acm.org/doi/10.1145/3730567.3764495
website: https://mpiclabs.org/marcopolo