New Microsoft Exchange 'ProxyToken' Flaw Lets Attackers Reconfigure Mailboxes
Aug 31, 2021
Details have emerged about a now-patched security vulnerability impacting Microsoft Exchange Server that could be weaponized by an unauthenticated attacker to modify server configurations, thus leading to the disclosure of Personally Identifiable Information (PII). The issue, tracked as CVE-2021-33766 (CVSS score: 7.3) and coined " ProxyToken ," was discovered by Le Xuan Tuyen, a researcher at the Information Security Center of Vietnam Posts and Telecommunications Group (VNPT-ISC), and reported through the Zero-Day Initiative (ZDI) program in March 2021. "With this vulnerability, an unauthenticated attacker can perform configuration actions on mailboxes belonging to arbitrary users," the ZDI said Monday. "As an illustration of the impact, this can be used to copy all emails addressed to a target and account and forward them to an account controlled by the attacker." Microsoft addressed the issue as part of its Patch Tuesday updates for July 2021...
