Microsoft warns of a critical vulnerability (CVE-2025-53786) in Exchange Server hybrid setups that could allow privilege escalation in Exchange Online without detection. Addressing this flaw is crucial to prevent total domain compromise, especially as attackers may exploit it more readily.
#ExchangeServer #PrivilegeEscalation #CVE202553786
#ExchangeServer #PrivilegeEscalation #CVE202553786
Keypoints
- The vulnerability affects Exchange Server 2016, 2019, and Subscription Edition in hybrid configurations.
- Attackers controlling on-premises Exchange can forge trusted tokens, impacting cloud security.
- Malicious activities on-premises may not be fully logged or detected in Microsoft 365 audits.
- Microsoft recommends applying April 2025 hotfix updates and reviewing service principals to mitigate risks.
- Failure to address this issue could lead to complete domain compromise and security breaches.