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.
Source: nakedsecurity
Industry: Unified communication news

Latest Jobs
-
- CIAM Architect Azure B2C
- N/A
- N/A
-
We are seeking a highly skilled and experienced Azure B2C CIAM Architect for a contract starting on Jan 2024. As an Azure B2C CIAM Architect, you will be responsible for designing, implementing, and deploying an new Azure B2C Solution . Responsibilities: Design and implement an Azure B2C-based CIAM solution that meets the needs of our clients organization. Maintain and support the Azure B2C-based CIAM solution. Provide training and support to our employees on the use of the CIAM solution. Background designing, implementing, and maintaining CIAM solutions. Experience with cloud-based identity and access management (IAM) solutions. Experience with OAuth, OpenID Connect,and SAML. Excellent written and verbal communication skills
-
- Senior IAM Consultant
- Germany
- Upto €110,000 depending on level of position
-
Senior IAM Consultant is needed to help lead and deploy IAM Projects for this expand IAM Consultancy The ideal candidate will have a deep understanding of IAM concepts and technologies, as well as experience in deploying and managing complex IAM solutions. Responsibilities Lead the deployment of IAM solutions for our clients Work with clients to understand their IAM requirements and design solutions that meet their needs Configure and implement IAM solutions using best practices Integrate IAM solutions with other enterprise systems Provide training and support to clients on the use of IAM solutions Stay up-to-date on the latest IAM technologies and trends We are looking for an experieneced IAM Consutlatn with: Strong understanding of IAM concepts and technologies,including identity lifecycle management,access control,and authentication Experience in deploying and managing complex IAM solutions Experience with IAM products and solutions,such as SailPoint,One Identity Manager,and Azure Active Directory Excellent communication and interpersonal skills Ability to work independently and as part of a team Fluent in German Candidates witll need to live and have the right to work within Germany to be considered.
-
- Security Architect - SOC Design - Outside IR35 London. SC / DV cleared
- London
- Outside IR35
-
Security Architect - With in-depth SOC Design experience needed for Outside IR35 London. SC / DV cleared. 6 month rolling Immediate Experience delivering technical Security Architecture design / assurance of security design with mobile network experience. HLD / LLD Current SC Clearance a must. Willingness to undertake DV. London 3 days a week Immediately interviewing.
-
- Cyber Security Risk Consultant. UK. Hybrid. Home | Work balance
- United Kingdom
- N/A
-
Cyber Security Consultancy - done the right way. Seeking a passionate Cyber Security Risk Consultant who enjoys helping clients make a different to their business. Warning- if you want a large, slow moving, high politics, high travel security consultancy that demands their a pound of flesh this is NOT for you. A successful individual will have experience working with clients to identify business cyber security risk. This is a remote first opportunity which means you will spend the majority of your time working remotely. You will however spend some time meeting clients as well as meeting up with the team on a monthly basis.. Some of the nice to have certifications. CRISC, ISO27001 Lead implementer, CISA, CISM, CISSP Along with dedicated training budgets, unlimited holiday and a structured career path, this opportunity will give a much needed work life balance. Unable to offer Visa sponsorship now or in the future. Apply and book a call in my diary with the below