An elevation of privilege vulnerability exists in Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could attempt to impersonate any other user of the Exchange server.
\nTo exploit the vulnerability, an attacker would need to execute a man-in-the-middle attack to forward an authentication request to a Microsoft Exchange Server, thereby allowing impersonation of another Exchange user.
\nTo address this vulnerability, a registry value which enables NTLM authentication on the network loopback adapter needs to be removed. Future cumulative updates will ensure that this registry setting is configured correctly during installation of the cumulative update.
\n","cweList":[],"cweDetailsListForSearch":[],"unformattedDescription":"An elevation of privilege vulnerability exists in Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could attempt to impersonate any other user of the Exchange server.\n\nTo exploit the vulnerability, an attacker would need to execute a man-in-the-middle attack to forward an authentication request to a Microsoft Exchange Server, thereby allowing impersonation of another Exchange user. \n\nTo address this vulnerability, a registry value which enables NTLM authentication on the network loopback adapter needs to be removed. Future cumulative updates will ensure that this registry setting is configured correctly during installation of the cumulative update.","mitreText":"CVE-2018-8581","mitreUrl":"https://www.cve.org/CVERecord?id=CVE-2018-8581","publiclyDisclosed":"No","exploited":"No","latestSoftwareReleaseId":2,"latestSoftwareRelease":"Exploitation Less Likely","olderSoftwareReleaseId":2,"olderSoftwareRelease":"Exploitation Less Likely","denialOfService":"N/A","tag":"Microsoft Exchange Server","issuingCna":"Microsoft","issuingCnaId":0,"severityId":100000001,"severity":"Important","impactId":100000002,"impact":"Elevation of Privilege","langCode":"en-US","isMariner":false,"customerActionRequired":true,"customerActionRequiredId":0,"cweDetailsList":[],"articles":[{"articleType":"FAQ","description":"A registry value DisableLoopbackCheck exists under the registry key HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\Lsa. The vulnerability described by CVE-2018-8581 is unexploitable if the DisableLoopbackCheck registry value is removed.
\nTo remove the registry value, type the following command in an elevated CMD window:
\nreg delete HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\Lsa /v DisableLoopbackCheck /f
Neither a restart of the operating system nor the Exchange Server is required after the removal of this registry value.
\nNote: It is important to remove only the DisableLoopbackCheck value. Care should be taken to not remove the Lsa key.
\n","ordinal":10000}],"revisions":[{"cveNumber":"CVE-2018-8581","version":1,"revisionDate":"2018-11-13T08:00:00Z","initialDate":"0001-01-01T00:00:00Z","description":"Information published.
\n","unformattedDescription":"Information published.","notificationNeeded":false,"notificationSent":false,"sourceId":"d1bedf77-9fd4-e811-a983-000d3a33a34d"},{"cveNumber":"CVE-2018-8581","version":1.1,"revisionDate":"2019-01-03T08:00:00Z","initialDate":"0001-01-01T00:00:00Z","description":"The FAQ was updated to clarify that the registry value should be deleted rather than the registry key. This is an informational change only.
\n","unformattedDescription":"The FAQ was updated to clarify that the registry value should be deleted rather than the registry key. This is an informational change only.","notificationNeeded":false,"notificationSent":false,"sourceId":"b96352c7-ae0e-e911-a98a-000d3a33c573"}]}]}