Security News > 2022 > October > Mitigation for Exchange Zero-Days Bypassed! Microsoft Issues New Workarounds

Microsoft has revised its mitigation measures for the newly disclosed and actively exploited zero-day flaws in Exchange Server after it was found that they could be trivially bypassed.

The two vulnerabilities, tracked as CVE-2022-41040 and CVE-2022-41082, have been codenamed ProxyNotShell due to similarities to another set of flaws called ProxyShell, which the tech giant resolved last year.

In-the-wild attacks abusing the shortcomings have chained the two flaws to gain remote code execution on compromised servers with elevated privileges, leading to the deployment of web shells.

To reduce the risk of exploitation, the company also shared temporary workarounds that are designed to restrict known attack patterns through a rule in the IIS Manager.

Microsoft has since revised the URL Rewrite rule to take this into account -.

It's not immediately clear when Microsoft plans to push a patch for the two vulnerabilities, but it's possible that they could be shipped as part of Patch Tuesday updates next week on October 11, 2022.

News URL

https://thehackernews.com/2022/10/mitigation-for-exchange-zero-days.html