Microsoft Patch Tuesday for March 2021 — Snort rules and prominent vulnerabilities

Summary: Microsoft's March 2021 security update disclosed 89 vulnerabilities, the most in any month that year, including 14 critical and one rated low severity. Three of the critical flaws were the Exchange Server vulnerabilities Microsoft said state-sponsored actors exploited in the wild to steal emails, and Microsoft also released patches for older Exchange Server versions.
Bottom line: State-sponsored actors were already using the Exchange flaws to steal email before patches existed, and Talos notes that blocking port 443 or requiring VPN access only stops the first step of the attack - administrators still have to apply the patches to close it.

Read the original at Cisco Talos ↗

Topics: Vulnerabilities & Patching
Mentions: CVE-2021-21300 CVE-2021-26411 CVE-2021-26877 CVE-2021-26893 CVE-2021-26894 CVE-2021-26895 CVE-2021-26896 CVE-2021-26897 CVE-2021-27063 CVE-2021-27085
Related: CVE-2021-27085: Microsoft Internet Explorer Remote Code Execution Vulnerability Known Exploited Vulnerabilities · Nov 03, 2021
CVE-2021-26411: Microsoft Internet Explorer Memory Corruption Vulnerability Known Exploited Vulnerabilities · Nov 03, 2021
Microsoft Patch Tuesday, March 2021 Edition Cyber Risks ·