CVE-2019-0858 — A spoofing vulnerability exists in Microsoft Exchange Server when Outlook Web Ac

A spoofing vulnerability exists in Microsoft Exchange Server when Outlook Web Access (OWA) fails to properly handle web requests, aka 'Microsoft Exchange Spoofing Vulnerability'. This CVE ID is unique from CVE-2019-0817.

01What is this vulnerability?

A spoofing vulnerability exists in Microsoft Exchange Server when Outlook Web Access (OWA) fails to properly handle web requests, aka 'Microsoft Exchange Spoofing Vulnerability'. This CVE ID is unique from CVE-2019-0817.

02Affected products

Vendor	Product	Versions
Microsoft	Microsoft Exchange Server	2019
Microsoft	Microsoft Exchange Server 2016	Cumulative Update 11, Cumulative Update 12
Microsoft	Microsoft Exchange Server 2013	Cumulative Update 22
Microsoft	Microsoft Exchange Server 2019	Cumulative Update 1

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

08Timeline

• Published: 2019-04-09T20:19:48.000Z
• Last modified: 2024-08-04T17:58:59.835Z

09References

• portal.msrc.microsoft.com — https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0858