Proxyshell

ProxyShell is a critical vulnerability affecting Microsoft Exchange email servers. It is a software design and implementation flaw that allows attackers to gain unauthorized access to the affected systems. The exploit chain for ProxyShell includes CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207. This vulnerability has been actively exploited by cybercriminals worldwide, with notable instances of targeting in Australia. The exploitation of this vulnerability became particularly urgent when it was reported that Iranian government-sponsored Advanced Persistent Threat (APT) actors were scanning for and exploiting this, along with other known vulnerabilities such as Fortinet FortiOS and Microsoft Exchange server vulnerabilities since early 2021. The APT groups have not only targeted ProxyShell but also other known vulnerabilities like ProxyLogon, tracked as CVE-2021-26855, and CVE-2021-26857, CVE-2021-26858, CVE-2021-27065. These attacks underline the importance of hardening and patching sensitive internet-facing assets. In response to these threats, the Cybersecurity and Infrastructure Security Agency (CISA) issued an alert urging organizations to protect against active exploitation of ProxyShell vulnerabilities. Furthermore, threat group BlackByte's use of the ProxyShell vulnerability represents a shift from their usual practice of scanning for and exploiting public-facing vulnerabilities to gain an initial foothold. To counter these threats, security measures such as Anti-Exploitation modules and Behavioral Threat Protection have been recommended. These protective measures can guard against the exploitation of different vulnerabilities including ProxyShell and ProxyLogon. They function by using behavioral analytics to defend against credential-based attacks. Cortex XDR Pro, delivered through Cortex XSIAM, offers Anti-Exploit protection that provides robust defense against the exploitation of various vulnerabilities including ProxyShell and ProxyLogon.