Zoom patches serious video conferencing bug
Zoom, a company that sells video conferencing software for the business market, patched a bug this week that could have allowed crooks to hijack customer video conferences.
Attackers with network access could have taken control of participating computers, according to researchers.
David Wells, a researcher at Tenable Security, reported the bug and provided an analysis including a proof of concept demonstration video explaining how attackers could compromise the Zoom system.
The vulnerability, which affected the Windows, Mac and Linux versions of Zoom’s software, lay in the way the company queued and processed messages in its software, Wells said.
This vulnerability affects the following Zoom versions:
- macOS 10.13, Zoom 4.1.33259.0925
- Windows 10, Zoom 4.1.33259.0925
- Ubuntu 14.04, Zoom 2.4.129780.0915
The internal mechanism that Zoom uses to send its network messages handles two kinds of network packet: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).
UDP doesn’t have the kind of handshaking and packet loss prevention overhead that you find in TCP packets, making it leaner and better suited for the latency-sensitive network communications that you find in audio and video conferencing.
TCP is therefore typically used to control sessions, while the simpler UDP protocol is used to send session content.
The messaging mechanism dispatches both kinds of packet to the same message handler program. Wells worked out a way to create a malformed UDP packet that the message handler interprets as a TCP message. The exploit works because the message handler isn’t validating the incoming messages to spot the malformed packet, according to Tenable’s synopsis.
The message handler accepts the UDP packets even when encrypted sessions are enabled, meaning that attackers do not need to authenticate themselves on the system first. That makes it possible for attackers outside of rogue meeting attendees to hijack a meeting. An attacker can be on the local network, or even on a WAN connection, suggests Wells, by brute-forcing the port that the victim is using for their UDP session with the Zoom server.
An attacker could take control of a computer by targeting a remote attendee sharing their screen during a session, said Tenable’s analysis. They could then bypass screen control permissions and send keystrokes and mouse movements directly to that participant’s machine. In practice, though, they’d have to avoid packet loss, which is a common occurrence in UDP sessions, and which could cause their keystrokes to go amiss. They would also have to avoid the victim noticing what they were doing and stopping them.
Tenable first gave Zoom the full details of this flaw on 11 October, and the video conferencing company released fixed versions for its Windows and Mac clients on 20 November, following up with a fix for the Linux client on 30 November.
Industry: Unified communication news
- Head of CSOC (Cyber Security Operations Centre), London. Greenfield opportunity
CH7928 Identifier Project Head of CSOC (Cyber Security Operations Centre), London. Greenfield UNIQUE opportunity to establish, manage and grow a world class CSOC. Headquartered in the UK, the CSOC will grow and deliver cyber services into an international and underdeveloped market. As a greenfield site the Head of CSOC will be the first person on the ground to build a capability and team around them. The role will include, but not be limited to; Setting up and establishing a CSOC monitoring service using IBM QRadar and Palo Alto CORTEX XSOAR. Develop roadmap for future CSOC capabilities. Establish, develop processes, playbooks and use cases. Recruit, Build and train a specialist team. Build relationships with key clients- onboard and scale. The successful candidate must have experience working within / leading a technical Cyber Security monitoring capability. Technical experience working with IBM QRadar and Palo Alto CORTEX XSOAR will be highly beneficial, although other SIEM / Security Orchestration, Automation and Response tools are welcome as the skillset is transferable. This brings significant opportunity and welcomes creativity / best practice. Frequent travel to London office will be required. Chris.email@example.com 07884666351
- Aruba Data Centre Network Engineer
- Upto £500 a day
**Outside of IR35 contract** Aruba Data Centre Network engineer is required to start ASAP. You will be responsible for Data Center and Campus Network - Design and implementation of Aruba CX Switches, We are looking for an experienced data centre engineer who is happy to work remotely and autonomously Experience you will need to have, Solid Networking experience with good knowledge of -Routing & Switching - MP-BGP EVPN VXLAN, MPLS/VPLS, EIGRP, BGP, OSPF and Multicast, Experience with Aruba switches ideally the CX range Ideally SC cleared or able to become SC Cleared. This will be a 3 month rolling contract
- Network Engineer-
- 65000 plus bonus
An exciting opportunity has arisen with a global financal business that are looking for an experienced Network engineer with strong Firewall experience in particular Checkpoint You will be responsible for help to support and manage the network infrastructure both LAN/ WAN And VPNs and will have a focus on network secuirty (Checkpoint firewall and Security controls) This is a multi-Site environment with few thousand end users, As the business is growing so is the network so great opportunity to join an expanding business that will help cross-train you in both cloud and onsite solutions. They are looking for a strong network engineer with a mix of expereience o Experience with Azure networking managing VNETs, ExpressRoute, VPNs and other Azure network features such as NSG/MS loadbalancer is required. Working with Check Point firewalls in Azure is desirable. o In-Depth understanding of networking fundamentals including: Network topology, Data Centre Infrastructure systems, Layer 2/Layer 3 Switching, VLANs, Routing, VPNs, High availability protocols. o Demonstrable hands-on experience with Meraki Switches and wireless infrastructure, Arista software, Forcepoint Proxy (would be a strongly desirable), Citrix Netscaler, and Forescout CounterACT Location can be flexible, they are looking for someone who would be happy to do a hybrid working model 3 days at home 2 days in the office.
- Technical Cyber Trainer, United Kingdom
Technical Cyber Trainer, United Kingdom Cyber trainer needed to build a new cyber training capability to develop a team of international security analysts. Technical Cyber training experience is a MUST. Any experience delivering technical Blue team based training is highly desired. This is a UK based role. Able to travel to London on occasion- when required. Agile, flexible working. A technical background is highly desirable and prefered. The role Aid in the setup, fine tuning and on-going customisation of Technical Cyber Security’s training platform. CyberBit experience desirable. Design, develop and deliver the internal syllabus to train employees with low cybersecurity knowledge to become analysts. Manage, monitor, support and assess learners. Fine tuning training and bespoke development. Manage, monitor and assess SOC analysts. Support employees through their career. The ability to deliver remote training is essential. This is a UK based role. Able to travel to London on occasion- when required. Agile working. Apply today to find out more information. Chris.Holt@dclsearch.com +447884666351