Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability

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 CVE ID is unique from CVE-2019-1221.

CheckOps priority index

7.6/10 Patch within 7 days

Severity7.5

Probability5.2

Exploitation5/5

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

EPSS · today 52.4% higher than 99.0% of CVEs

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

Exploited for 1,826 days 03 Nov 2021

CISA due date 03 May 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 5 / 5

KEV catalog (CISA)03 Nov 2021
Exploited in EUVD (ENISA)03 Nov 2021
Used by ransomwareyes
EPSS above 10 %52.4%
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

Affected products

Internet Explorer 11 on Windows 10 Version 1903 for x64-based SystemsInternet Explorer 11Internet Explorer 11 on Windows Server 2012Internet Explorer 10Internet Explorer 11 on Windows 10 Version 1903 for ARM64-based SystemsInternet Explorer 11 on Windows 10 Version 1903 for 32-bit SystemsInternet Explorer 9Internet Explorer

Affected versions

unspecified
Windows 10 Version 1803 for 32-bit Systems
Windows Server 2012 R2
Windows 7 for x64-based Systems Service Pack 1
Windows 10 Version 1803 for ARM64-based Systems
Windows 10 Version 1803 for x64-based Systems
Windows Server 2008 R2 for x64-based Systems Service Pack 1
Windows Server 2012
Windows 10 Version 1607 for 32-bit Systems
Windows 10 for 32-bit Systems
Windows 10 Version 1809 for 32-bit Systems
Windows Server 2019

Weaknesses (CWE)

CWE-787

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

23 Sept 2019
Published
03 Nov 2021
Exploitation reported (ENISA)
03 Nov 2021
Added to the KEV catalog
03 May 2022
CISA remediation due date
26 Sept 2026
EPSS peak: 52.4%

References

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