Expert publishes PoC exploit code for Microsoft Exchange flaws


This week a security researcher published on GitHub a proof-of-concept tool to hack Microsoft Exchange servers chaining two of ProxyLogon flaws.
On March 2nd, Microsoft has released emergency out-of-band security updates that address four zero-day issues (CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065) in all supported Microsoft Exchange versions that are actively exploited in the wild. The IT giant reported that at least one China-linked APT group, tracked as HAFNIUM, chained these vulnerabilities to access on-premises Exchange servers to access email accounts, and install backdoors to maintain access to victim environments. According to Microsoft, the Hafnium APT exploited these vulnerabilities in targeted attacks against US organizations.
This week, the independent security researcher Nguyen Jang published on GitHub a proof-of-concept tool to hack Microsoft Exchange servers. The tool chains two of the ProxyLogon vulnerabilities recently addressed by Microsoft.