CVE-2018-8378

An information disclosure vulnerability exists when Microsoft Office software reads out of bound memory due to an uninitialized variable, which could disclose the contents of memory, aka "Microsoft Office Information Disclosure Vulnerability." This affects Word, Microsoft SharePoint Server, Microsoft Office Word Viewer, Microsoft Excel Viewer, Microsoft SharePoint, Microsoft Office.

Published: 2018-08-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-8378 is rated Moderate Risk (60.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 32.80%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +5.86% over the last day, indicating growing attacker interest. 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-2018-8378

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 2026-05-07 26.94% 32.80% +5.86%
2 2026-01-03 32.42% 26.94% -5.48%
3 2025-12-28 — 32.42% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-8378

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:H/I:N/A:N 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N 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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2018-8378

Affected software / configurations for CVE-2018-8378

Vendor Product Version Raw CPE
microsoft excel_viewer 2007 cpe:2.3:a:microsoft:excel_viewer:2007:sp3:*:*:*:*:*:*
microsoft office 2010 cpe:2.3:a:microsoft:office:2010:sp2:*:*:*:*:*:*
microsoft office 2013 cpe:2.3:a:microsoft:office:2013:sp1:*:*:*:*:*:*
microsoft office 2013 cpe:2.3:a:microsoft:office:2013:sp1:*:*:rt:*:*:*
microsoft office 2016 cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:*:*
microsoft office 2016 cpe:2.3:a:microsoft:office:2016:*:*:*:click-to-run:*:*:*
microsoft office_compatibility_pack — cpe:2.3:a:microsoft:office_compatibility_pack:-:sp3:*:*:*:*:*:*
microsoft office_web_apps 2010 cpe:2.3:a:microsoft:office_web_apps:2010:sp2:*:*:*:*:*:*
microsoft office_web_apps 2013 cpe:2.3:a:microsoft:office_web_apps:2013:sp1:*:*:*:*:*:*
microsoft office_word_viewer — cpe:2.3:a:microsoft:office_word_viewer:-:*:*:*:*:*:*:*
microsoft sharepoint_enterprise_server_2013 — cpe:2.3:a:microsoft:sharepoint_enterprise_server_2013:-:sp1:*:*:*:*:*:*
microsoft sharepoint_enterprise_server_2016 — cpe:2.3:a:microsoft:sharepoint_enterprise_server_2016:-:*:*:*:*:*:*:*
microsoft sharepoint_server 2013 cpe:2.3:a:microsoft:sharepoint_server:2013:sp1:*:*:*:*:*:*
microsoft word_automation_services — cpe:2.3:a:microsoft:word_automation_services:-:*:*:*:*:*:*:*

References for CVE-2018-8378

cvelogic Threat Intelligence