CVE-2018-8547 — Active Directory Federation Services XSS Vulnerability

Executive Summary

A cross-site-scripting (XSS) vulnerability exists when an open source customization for Microsoft Active Directory Federation Services (AD FS) does not properly sanitize a specially crafted web request to an affected AD FS server. An authenticated attacker could exploit the vulnerability by sending a specially crafted request to an affected AD FS server. The attacker who successfully exploited the vulnerability could then perform cross-site scripting attacks on affected systems and run scripts in the security context of the current user. The attacks could allow the attacker to read content that the attacker is not authorized to read, use the victim's identity to take actions on the AD FS site on behalf of the user, such as change permissions and delete content, and inject malicious content in the browser of the user. The security update addresses the vulnerability by helping to ensure that the open source customization for AD FS properly sanitizes web requests.

Overview

6.5

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Spoofing

Released Nov 13 2018

Last Updated Nov 13 2018

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

CVSS Vector

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

None

AVAILABILITY

None

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 5.9

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

17 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1607 for 32-bit Systems	`4467691 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1607 for x64-based Systems	`4467691 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1709 for 32-bit Systems	`4467686 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1709 for x64-based Systems	`4467686 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1803 for 32-bit Systems	`4467702 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1803 for ARM64-based Systems	`4467702 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1803 for x64-based Systems	`4467702 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1809 for 32-bit Systems	`4467708 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1809 for ARM64-based Systems	`4467708 (Security Update)`	Important	Spoofing	Yes
Windows 10 Version 1809 for x64-based Systems	`4467708 (Security Update)`	Important	Spoofing	Yes
Windows 8.1 for 32-bit systems 4467697 (Monthly Rollup) 4467703 (Security Only) Important Spoofing 4462926 Base: 6.5 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows 8.1 for x64-based systems 4467697 (Monthly Rollup) 4467703 (Security Only) Important Spoofing 4462926 Base: 6.5 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows RT 8.1	`4467697 (Monthly Rollup)`	Important	Spoofing	Yes
Windows Server 2012 R2 4467697 (Monthly Rollup) 4467703 (Security Only) Important Spoofing 4462926 Base: 6.5 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows Server 2012 R2 (Server Core installation) 4467697 (Monthly Rollup) 4467703 (Security Only) Important Spoofing 4462926 Base: 6.5 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C Yes None Windows Server 2016	`4467691 (Security Update)`	Important	Spoofing	Yes
Windows Server 2016 (Server Core installation)	`4467691 (Security Update)`	Important	Spoofing	Yes
Windows Server 2019	`4467708 (Security Update)`	Important	Spoofing	Yes
Windows Server 2019 (Server Core installation)	`4467708 (Security Update)`	Important	Spoofing	Yes
Windows Server, version 1709 (Server Core Installation)	`4467686 (Security Update)`	Important	Spoofing	Yes
Windows Server, version 1803 (Server Core Installation)	`4467702 (Security Update)`	Important	Spoofing	Yes

Patches

5 patches

Article	Type	Restart
`4467691`	Security Update	Yes
`4467686`	Security Update	Yes
`4467702`	Security Update	Yes
`4467708`	Security Update	Yes
`4467697`	Monthly Rollup	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

None

References

MSRC Advisory MITRE NVD