CVE-2018-8558 — An information disclosure vulnerability exists when Microsoft Outlook fails to r

An information disclosure vulnerability exists when Microsoft Outlook fails to respect "Default link type" settings configured via the SharePoint Online Admin Center, aka "Microsoft Outlook Information Disclosure Vulnerability." This affects Office 365 ProPlus

01What is this vulnerability?

An information disclosure vulnerability exists when Microsoft Outlook fails to respect "Default link type" settings configured via the SharePoint Online Admin Center, aka "Microsoft Outlook Information Disclosure Vulnerability." This affects Office 365 ProPlus, Microsoft Office. This CVE ID is unique from CVE-2018-8579.

02Affected products

Vendor	Product	Versions
Microsoft	Microsoft Office	2019 for 32-bit editions, 2019 for 64-bit editions
Microsoft	Office	365 ProPlus for 32-bit Systems, 365 ProPlus for 64-bit Systems

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: 2018-11-14T01:00:00.000Z
• Last modified: 2024-08-05T07:02:25.441Z

09References

• www.securityfocus.com — http://www.securityfocus.com/bid/105826
• portal.msrc.microsoft.com — https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8558