Background exploitation KEV catalog No authentication

CVE-2018-8373

Microsoft Scripting Engine Memory Corruption Vulnerability

CheckOps priority index

7.3/10 Patch within 7 days

Severity7.5

Probability6.2

Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 61.8% +0.3 pts in 7 days

CVSS 3.1 7.5 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:

Exploited for 1,684 days 25 Mar 2022

CISA due date 15 Apr 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

KEV catalog (CISA)25 Mar 2022
Exploited in EUVD (ENISA)25 Mar 2022
Used by ransomwareno
EPSS above 10 %61.8%
No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka "Scripting Engine Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10. This CVE ID is unique from CVE-2018-8353, CVE-2018-8355, CVE-2018-8359, CVE-2018-8371, CVE-2018-8372, CVE-2018-8385, CVE-2018-8389, CVE-2018-8390.

Affected products

Internet Explorer 9Internet Explorer 11Internet Explorer 10Internet Explorer Scripting Engine

Affected versions

Windows Server 2008 for x64-based Systems Service Pack 2
Windows Server 2008 R2 for x64-based Systems Service Pack 1
Windows Server 2016
Windows 10 Version 1709 for 32-bit Systems
Windows 10 for x64-based Systems
Windows 10 Version 1703 for x64-based Systems
Windows 10 Version 1607 for x64-based Systems
Windows 7 for 32-bit Systems Service Pack 1
Windows 8.1 for 32-bit systems
Windows 10 Version 1703 for 32-bit Systems
Windows 10 Version 1709 for x64-based Systems
Windows RT 8.1

Weaknesses (CWE)

CWE-787

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

15 Aug 2018
Published
25 Mar 2022
Exploitation reported (ENISA)
25 Mar 2022
Added to the KEV catalog
15 Apr 2022
CISA remediation due date
26 Sept 2026
EPSS peak: 61.9%

References

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