Remote code execution via JScript use-after-free
Published Feb 11, 2020 · Updated Oct 21, 2025
Memory corruption in Microsoft Internet Explorer 9 through 11 allows remote attackers to execute code via crafted content. The legacy jscript.dll engine uses an object after its memory has been freed, corrupting memory under attacker control. Exploitation requires user interaction with crafted HTML or another document embedding the engine, and legacy JScript must be selected instead of the default jscript9.dll; code runs as the current user.
Summary
What happened
Memory corruption in Microsoft Internet Explorer 9 through 11 allows remote attackers to execute code via crafted content. The legacy jscript.dll engine uses an object after its memory has been freed, corrupting memory under attacker control. Exploitation requires user interaction with crafted HTML or another document embedding the engine, and legacy JScript must be selected instead of the default jscript9.dll; code runs as the current user.
The record
- CVE
- CVE-2020-0674
- Published
- Feb 11, 2020
- Updated
- Oct 21, 2025
- Vendor
- Microsoft
- Product
- Internet Explorer 10
- Classifications
- CWE-416, T1189, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 11, 2020CVE publishedPublication date reported by the CVE source.
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Windows Server 2012
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- maxpl0it CVE-2020-0674 proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities catalog entryknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo