Google Details Two Zero-Day Bugs Reported in Zoom Clients and MMR Servers

An exploration of zero-simply click attack surface area for the common video clip conferencing solution Zoom has yielded two beforehand undisclosed security vulnerabilities that could be exploited to crash the service, execute destructive code, and even leak arbitrary parts of its memory.

Natalie Silvanovich of Google Task Zero, who found and reported the two flaws past 12 months, said the issues influence both of those Zoom clients and Multimedia Router (MMR) servers, which transmit audio and movie material in between purchasers in on-premise deployments.

The weaknesses have due to the fact been addressed by Zoom as section of updates delivered on November 24, 2021.

The aim of a zero-click attack is to stealthily obtain command above the victim’s machine without having requiring any variety of conversation from the person, these types of as clicking on a backlink.

Even though the particulars of the exploit will vary depending on the mother nature of vulnerability staying exploited, a key trait of zero-simply click hacks is their capacity not to go away behind traces of malicious action, generating them quite challenging to detect.

The two flaws identified by Undertaking Zero are as follows —

• CVE-2021-34423 (CVSS rating: 9.8) – A buffer overflow vulnerability that can be leveraged to crash the provider or software, or execute arbitrary code.
• CVE-2021-34424 (CVSS score: 7.5) – A system memory exposure flaw that could be made use of to most likely obtain perception into arbitrary places of the product’s memory.

By analyzing the RTP (Genuine-time Transportation Protocol) targeted traffic used to supply audio and movie more than IP networks, Silvanovich discovered that it can be attainable to manipulate the contents of a buffer that supports looking at distinct information forms by sending a malformed chat information, leading to the client and the MMR server to crash.

Additionally, the deficiency of a NULL verify — which is made use of to ascertain the conclude of a string — created it feasible to leak details from the memory by becoming a member of a Zoom meeting by way of a web browser.

The researcher also attributed the memory corruption flaw to the point that Zoom failed to enable ASLR, aka tackle room structure randomization, a security mechanism created to enhance the problem of accomplishing buffer overflow attacks.

“The lack of ASLR in the Zoom MMR procedure enormously improved the risk that an attacker could compromise it,” Silvanovich reported. “ASLR is arguably the most crucial mitigation in stopping exploitation of memory corruption, and most other mitigations count on it on some stage to be successful. There is no very good purpose for it to be disabled in the extensive the vast majority of software program.”

Although most online video conferencing systems use open up-resource libraries these as WebRTC or PJSIP for implementing multimedia communications, Project Zero called out Zoom’s use of proprietary formats and protocols as very well as its superior licensing service fees (approximately $1,500) as limitations to security study.

“Shut-resource program offers exclusive security troubles, and Zoom could do extra to make their system obtainable to security scientists and some others who desire to examine it,” Silvanovich mentioned. “Although the Zoom Security Staff helped me entry and configure server software package, it is not crystal clear that help is accessible to other researchers, and licensing the software package was continue to highly-priced.”

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Some elements of this short article are sourced from:
thehackernews.com