CVE-2017-8542

The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to denial of service. aka "Microsoft Malware Protection Engine Denial of Service Vulnerability", a different vulnerability than CVE-2017-8535, CVE-2017-8536, CVE-2017-8537, and CVE-2017-8539.

Published: 2017-05-26 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-8542 is rated Moderate Risk (55.8/100): CVSS Medium severity, with high exploitation likelihood (EPSS 19.18%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-8542

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 18.62% 19.18% +0.56%
2 2025-03-29 19.18% 18.62% -0.56%
3 2025-03-19 — 19.18% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-8542

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.0 MEDIUM
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2017-8542

Affected software / configurations for CVE-2017-8542

Vendor Product Version Raw CPE
microsoft forefront_security — cpe:2.3:a:microsoft:forefront_security:-:*:*:*:*:*:*:*
microsoft malware_protection_engine <= 1.1.13704.0 cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:*
microsoft windows_defender — cpe:2.3:a:microsoft:windows_defender:-:*:*:*:*:*:*:*

References for CVE-2017-8542

cvelogic Threat Intelligence