Sequoia: A Local Privilege Escalation Vulnerability in Linux’s Filesystem Layer – . Wheel – PSW #707

August 20, 2021

The Qualys Research Team discovered a size_t-to-int type conversion vulnerability in the Linux Kernel’s filesystem layer affecting most Linux operating systems. Any unprivileged user can gain root privileges on a vulnerable host by exploiting this vulnerability in a default configuration. Successful exploitation of this vulnerability allows any unprivileged user to gain root privileges on the vulnerable host. Qualys security researchers have been able to independently verify the vulnerability, develop an exploit, and obtain full root privileges on default installations of Ubuntu 20.04, Ubuntu 20.10, Ubuntu 21.04, Debian 11, and Fedora 34 Workstation. Other Linux distributions are likely vulnerable and probably exploitable.

Segment Resources:
https://blog.qualys.com/vulnerabilities-threat-research/2021/07/20/sequoia-a-local-privilege-escalation-vulnerability-in-linuxs-filesystem-layer-cve-2021-33909 Visit https://www.securityweekly.com/psw for all the latest episodes!

Full Episode Show Notes

Sequoia: A Local Privilege Escalation Vulnerability in Linux’s Filesystem Layer

Guests

. Wheel

. Wheel - Researcher at Qualys

“Wheel” is a member of the Qualys Research Team responsible for finding zero-days.

Hosts

Lee Neely

Lee Neely - Senior Cyber Analyst at Lawrence Livermore National Laboratory

@lelandneely

Lee Neely is a senior IT and security professional at Lawrence Livermore National Laboratory (LLNL) with over 25 years of experience. He has been involved in many aspects of IT from system integration and quality testing to system and security architecture since 1986. He has had extensive experience with a wide variety of technology and applications from point implementations to enterprise solutions. Lee has worked with securing information systems since he installed his first firewall in 1989.

Paul Asadoorian

Paul Asadoorian - Founder at Security Weekly

@securityweekly

Paul Asadoorian is the founder of Security Weekly, which was acquired by CyberRisk Alliance. Paul spent time “in the trenches” implementing security programs for a lottery company and then a large university. Paul is offensive, having spent several years as a penetration tester. As Product Evangelist for Tenable Network Security, Paul built a library of materials on the topic of vulnerability management. When not hacking together embedded systems (or just plain hacking them) or coding silly projects in Python, Paul can be found researching his next set of headphones.

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