DEFCON 29 IoT Village - Ken Pyle - BLUEMONDAY Series Exploitation and Mapping of Vulnerable Devices
Channel: DEFCONConference
Date: 31/08/2021

Vendors like DATTO, MERAKI, GEOVISION, SYNOLOGY, EGNYTE and others are which leverage or depend on these services are imperiling data, networks, and businesses through insecure design, intentional design decisions, and web application flaws.

These devices frequently self-provision services which leak critical data or through insecure network design and installation practices which are easily mapped, attacked, and discovered via insecure vendor, software, and integrator practices (ex. PKI, Dynamic DNS, “Finder” service registrations, DNS leakage, Layer 2 Attacks / DHCP network attacks, DNS passive hijacking through domain purchases & active record injection) 

Some concepts and new attacks may be obliquely referenced or held private by the researcher. Essential PoC is contained in this document and is easily reproduced using supplied narrative and screenshots.

The affected devices are easily discoverable either through insecure practices (ex. insecure Zones, algorithmic FQDN generation, lack of local network controls, public metadata leakage) or vendor provided interfaces and access methods. (DATTOWEB, DATTOLOCAL, SYNOLOGY.ME, DYNAMIC-M, GVDIP.COM, EGNYTE-APPLIANCE.COM)

Many issues develop due to these problems. For example, nearly all of these devices and appliances provide easily discoverable portals / content / metadata with which to craft extremely convincing social engineering campaigns, even in the absence of technical exploit vectors. 

Host Header Attacks & 302 redirects used in concert with malicious DNS records / spoofed or squatted domains can be abused in this manner. An attacker can identify the MERAKI device a victim uses through registration, abuse the API to obtain sensitive metadata, and send the victim to a spoofed site or malicious content purported to be a Meraki Dashboard alert. An attacker can change the dynamic DNS record through a number of vectors (ex. Third party service attacks, local vectors) and effectively “hijack” the user or content being accessed.

Through our DNS harvesting and our undisclosed 0-days, we can establish a complex exploit network and botnet via poor vendor controls (ex. MIRAI) We can also hide exploit code in APIs, persist across multiple appliance types, and abuse multiple dynamic DNS networks.

The DNS zones we have provided are intentionally designed, demonstrably insecure, provide detailed information, and can be abused easily. Registrations can be abused for data exfiltration or beaconing over the vendor’s DNS network. These DYNAMIC DNS services allow for efficient, mass exploitation and recon. The poor controls and “spoofability” of these networks (will demonstrate at another time) allow an attacker to not only FIND vulnerable devices.. but automate mass exploitation via attacks such as those we provided or other common attacks. 

The author wishes for this to be noted as responsible disclosure and ethical considerations for the attacks / exploits seriously impacted disclosure dates and continues to.

Some initial work can be found here:

https://cybir.com/2021/cyber-security/bluemonday-series-part-1-exploitation-mapping-of-vulnerable-devices-at-scale-through-self-registration-services/