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ProxyNotShell Proof-of-Concept Published Online

Security researchers confirm Proof-of-Concept (PoC) works against unpatched versions of Microsoft Exchange Server 2013, 2016 and 2019 In early August, researchers discovered cyberattacks against critical infrastructure using two unpublished Exchange Server security vulnerabilities. Microsoft’s Security Research Center (MSRC) stated: “The first exploit identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, and the second one, identified as CVE-2022-41082, allows [...]

Microsoft November 2022 Patch Tuesday: Exchange Server Security Updates

Microsoft has released security updates for two zero-day vulnerabilities: CVE-2022-41040, a server-side request forgery vulnerability, and CVE-2022-41082, which allows remote code execution. Collectively known as ProxyNotShell, the Exchange Server vulnerabilities have led to a spate of attacks linked to nation-state threat actors since late September. The SUs address vulnerabilities responsibly reported to Microsoft by security [...]

Microsoft October 2022 Patch Tuesday: Exchange Server Security Updates

The SUs address vulnerabilities responsibly reported to Microsoft by security partners and found through Microsoft’s internal processes. Our recommendation is to immediately install these updates to protect your environment. NOTE   The October 2022 SUs do not contain fixes for the zero-day vulnerabilities reported publicly on September 29, 2022 (CVE-2022-41040 and CVE-2022-41082). Please see this blog post to apply mitigations for those [...]

Alert: New Zero-Day Vulnerability Targets Microsoft On-Premise and Hybrid Cloud Exchange Servers

Summary: In early August, researchers from the cybersecurity vendor GTSC discovered cyberattacks against critical infrastructure using two unpublished Exchange Server security vulnerabilities. Microsoft’s Security Research Center (MSRC) stated: “The first exploit identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, and the second one, identified as CVE-2022-41082, allows Remote Code Execution (RCE) when PowerShell [...]

Exchange Online Servers Hacked Using Malicious OAuth Applications

Microsoft’s 365 Defender Research Team recently investigated an attack in which malicious OAuth applications were deployed on compromised cloud tenants. Initial Access The attacker first needed to compromise a cloud user’s account that had sufficient permissions in order to create a malicious OAuth application. The threat actor did this by launching credential-stuffing attacks against high-risk [...]

CISA Publishes Mitigation Techniques Against Exchange Server Attacks

In response to the recent targeting of critical infrastructure in the US and abroad, the Cybersecurity and Infrastructure Security Agency (CISA) urges network and security administrators to prepare and immediately mitigate potential cyber threats with the following measures. Implement and apply backup and recovery policies and procedures: Maintain offline backups of dataRegularly test backup and restorationEnsure all backup [...]

Nemesis Kitten targets Exchange Server for Attacks

Microsoft Security Threat Intelligence has been tracking multiple ransomware campaigns by a group known as DEV-0270 who also goes by the alias Nemesis Kitten. Who is DEV-0270? DEV-0270, a sub-group of the Iranian threat actor known as PHOSPHORUS, are known for leveraging newly disclosed vulnerabilities against their targets. If successful, the group contacts the victim [...]

Microsoft Exchange Server Security: The 10 Best Ways to Secure Your Server

Security breaches cause organizational chaos, financial and reputation risk. Given how organizations have shifted to a hybrid of in-office and work-from-home, there is a significant increase in the security threat landscape, and it’s more important than ever to improve and harden Exchange Server security. These best practices help provide a baseline security framework that all [...]

Microsoft August 2022 Patch Tuesday: Exchange Server vulnerabilities fixed

Microsoft has released security updates (SUs) for vulnerabilities found in: Exchange Server 2013Exchange Server 2016Exchange Server 2019 The SUs address vulnerabilities responsibly reported to Microsoft by security partners and found through Microsoft’s internal processes. Although we are not aware of any active exploits in the wild, our recommendation is to immediately install these updates to protect your [...]