Cyber Resilience

CVE-2020-1380

Memory Safety in Microsoft Internet Explorer 11

CISA KEVActive ExploitationEUVD ExploitedPublic PoCMemory Safety
Published
17 August 2020
Modified
23 February 2026
KEV Added
03 November 2021
Patch / advisory
View advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.24 98th percentile
Risk Priority 83 floored blend · peak EPSS

Summary

CVE-2020-1380 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Microsoft Windows Server 2012. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A remote code execution vulnerability exists in the way the scripting engine handles objects in memory in Internet Explorer. Successful exploitation can corrupt memory and allow arbitrary code execution in the context of the current user, potentially leading to full system compromise if the user has administrative rights. The issue is tracked as CWE-787 and carries a CVSS 3.1 score of 7.8.

An attacker can exploit the flaw in a web-based scenario by hosting a specially crafted site that targets Internet Explorer or by embedding an ActiveX control marked safe for initialization in a Microsoft Office document or other application that hosts the IE rendering engine. Compromised or user-generated content sites can also serve as vectors. Exploitation grants the attacker the same privileges as the logged-on user, enabling installation of programs, data access or modification, and creation of new accounts.

Microsoft's security update addresses the vulnerability by modifying how the scripting engine handles objects in memory, as detailed in the MSRC advisory for CVE-2020-1380. The flaw appears in the CISA Known Exploited Vulnerabilities catalog, and public proof-of-concept material targeting jscript9.dll has been published.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-787
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2020-0968Same product: Microsoft Internet Explorerboth on KEV
CVE-2020-0878Same product: Microsoft Internet Explorerboth on KEV
CVE-2020-1020Same product: Microsoft Windows 10 1507both on KEV
CVE-2018-8653Same product: Microsoft Internet Explorerboth on KEV
CVE-2019-1367Same product: Microsoft Internet Explorerboth on KEV
CVE-2020-1027Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-0938Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-1054Same product: Microsoft Windows 10 1507both on KEV
CVE-2021-33742Same product: Microsoft Windows 10 1507both on KEV
CVE-2021-34448Same product: Microsoft Windows 10 1507both on KEV

Affected Assets

microsoft
internet explorer
11

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect and prevent out-of-bounds write defects.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that prevent out-of-bounds writes.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory handling.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

A.8.28 Secure coding partial match
prevents

Secure coding directly addresses out-of-bounds writes through language choice and coding standards.

A.8.32 Change management partial match
prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References