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- Apr 24, 2016
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Today is Microsoft's March 2023 Patch Tuesday, and security updates fix two actively exploited zero-day vulnerabilities and a total of 83 flaws.
Nine vulnerabilities have been classified as 'Critical' for allowing remote code execution, denial of service, or elevation of privileges attacks.
The number of bugs in each vulnerability category is listed below:
This count does not include twenty-one Microsoft Edge vulnerabilities fixed yesterday.
- 21 Elevation of Privilege Vulnerabilities
- 2 Security Feature Bypass Vulnerabilities
- 27 Remote Code Execution Vulnerabilities
- 15 Information Disclosure Vulnerabilities
- 4 Denial of Service Vulnerabilities
- 10 Spoofing Vulnerabilities
- 1 Edge - Chromium Vulnerability
Two zero-days fixed
This month's Patch Tuesday fixes two zero-day vulnerabilities actively exploited in attacks.
Microsoft classifies a vulnerability as a zero-day if it is publicly disclosed or actively exploited with no official fix available.
The two actively exploited zero-day vulnerabilities fixed in today's updates are:
CVE-2023-23397 - Microsoft Outlook Elevation of Privilege Vulnerability
Microsoft has fixed a Microsoft Outlook privilege elevation bug that allows specially crafted emails to force a target's device to connect to a remote URL and transmit the Windows account's Net-NTLMv2 hash.
"External attackers could send specially crafted emails that will cause a connection from the victim to an external UNC location of attackers' control. This will leak the Net-NTLMv2 hash of the victim to the attacker who can then relay this to another service and authenticate as the victim.," reads Microsoft's advisory.
Microsoft warns that this flaw will be triggered before it is read in the preview pane as the vulnerability "triggers automatically when it is retrieved and processed by the email server."
This vulnerability was disclosed by CERT-UA, Microsoft Incident, Microsoft Threat Intelligence (MSTI).
CVE-2023-24880 - Windows SmartScreen Security Feature Bypass Vulnerability
Microsoft has fixed an actively exploited zero-day vulnerability in Windows SmartScreen that was previously exploited to distribute and install malware.
"An attacker can craft a malicious file that would evade Mark of the Web (MOTW) defenses, resulting in a limited loss of integrity and availability of security features such as Protected View in Microsoft Office, which rely on MOTW tagging," reads Microsoft's advisory.
When exploited, the malicious file can run without triggering a Mark of the Web (MoTW) security warning.
This vulnerability was disclosed by Benoît Sevens and Vlad Stolyarov of Google’s Threat Analysis Group and Bill Demirkapi of Microsoft.
Microsoft March 2023 Patch Tuesday fixes 2 zero-days, 83 flaws
Today is Microsoft's March 2023 Patch Tuesday, and security updates fix two actively exploited zero-day vulnerabilities and a total of 83 flaws.
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