CVE-2020-1380 — 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. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the scripting engine handles objects in memory.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Exploited by 1 threat actor(s) (MITRE ATT&CK)+10
- EPSS 24.2% (30-day exploitation probability)+15
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — portal.msrc.microsoft.com (NIST National Vulnerability Database)
CISA required action CISA
Apply updates per vendor instructions.
US federal deadline: May 3, 2022 — passed 1626 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Microsoft Internet Explorer, Microsoft Internet Explorer 11).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 98% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Microsoft | Internet Explorer | version 11 | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Internet Explorer 11 | ≥ 1.0.0 and < publication | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | secure@microsoft.com via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | microsoft via CVE Program (cve.org) e CISA ADP |
| 7.5 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.6 | CVSS 2.0 | High | 4.9 | 10.0 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: secure@microsoft.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
Threat actors exploiting this CVE MITRE ATT&CK
According to MITRE ATT&CK.
APT37 G0067EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 24.19%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
- Hunt retroactively in logs from before Nov 3, 2021 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · microsoft/internet explorer 11
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · microsoft/internet explorer
- CVSS changed · 7.8
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- 2021
- Added to CISA KEV catalog
- 2020
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
5 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2021-27085 Microsoft Internet Explorer Remote Code Execution Vulnerability KEV Mar 11, 2021
- High CVE-2021-26411 Microsoft Internet Explorer Memory Corruption Vulnerability KEV Mar 11, 2021
- Medium CVE-2020-0878 Microsoft Edge and Internet Explorer Memory Corruption Vulnerability KEV Sep 11, 2020
- High CVE-2020-0968 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Apr 15, 2020
- High CVE-2020-0674 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Feb 11, 2020
- High CVE-2019-1429 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Nov 12, 2019
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2020-1380 is "Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability", rated High. It affects Internet Explorer (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 24.19% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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