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Oct 19, 2021
Hackers Infect Employees of Law Firms, Manufacturing Companies, and Financial Services Orgs. with Increasingly Pervasive Infostealer, SolarMarker
SolarMarker Infects 5X More Corporate Victims Using Over a Million Poisoned WordPress Pages Key Takeaways eSentire has observed a fivefold increase in SolarMarker infections. Prior to September, eSentire’s Threat Response Unit (TRU) detected and shut down one infection per week. Beginning in September, TRU averaged the detection and shutdown of five per week. SolarMarker is a…
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Waterloo, ON – Oct. 12, 2021 -- eSentire, recognized globally as the Authority in Managed Detection and Response (MDR), today announced the expansion of its award-winning MDR services with Microsoft Azure Sentinel, as part of its integration with the complete Microsoft 365 Defender and Azure Defender product suites supporting Microsoft SIEM, endpoint, identity, email and cloud security services.…
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Security advisories — Jul 20, 2021

CVE-2021-33909 - Linux LPE Vulnerability

THE THREAT

Security researchers from Qualys have announced a Local Privilege Escalation (LPE) vulnerability impacting the Linux operating system. The vulnerability is tracked as CVE-2021-33909 and has been alternatively named Sequoia. Exploitation would allow a threat actor with previous access to a vulnerable system to run code with root privileges. Proof-of-Concept (PoC) exploit code is publicly available; at this time the exploit code only allows for denial-of-service, but it is expected to be modified for LPE in the near future.

The Sequoia vulnerability has been confirmed to impact Debian, Ubuntu, and Fedora; other Linux distributions are likely vulnerable but have not been confirmed at this point. Organizations are strongly recommended to apply security patches as they are released by individual Linux distributions.

What we’re doing about it

What you should do about it

Additional information

Exploitation of CVE-2021-33909 has not been identified in the wild at this time. Exploitation is expected in the near future, as PoC code is publicly available, reducing the barriers of exploitation for threat actors.

Qualys has tested the exploit against installations of Ubuntu 20.04, Ubuntu 20.10, Ubuntu 21.04, Debian 11, and Fedora 34 Workstation. It is highly likely that other Linux distributions are impacted.

Qualys has released two mitigations for CVE-2021-33909. Despite mitigations, the primary recommendation is for organizations to apply the relevant security patches as soon as possible. It should be noted that both of the following mitigations may be bypassed.

References:

[1] https://www.qualys.com/2021/07/20/cve-2021-33909/sequoia-local-privilege-escalation-linux.txt