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PatchSiren cyber security CVE debrief

CVE-2020-1380 Microsoft CVE debrief

CVE-2020-1380 is a Microsoft Internet Explorer Scripting Engine memory corruption vulnerability that CISA added to its Known Exploited Vulnerabilities catalog on 2021-11-03. Because it is listed as known exploited, defenders should treat it as a high-priority remediation item and follow vendor update guidance.

Vendor
Microsoft
Product
Internet Explorer
CVSS
HIGH 7.8
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

Organizations that still run or support Internet Explorer, legacy web applications that depend on IE components, and endpoint teams responsible for patching Windows systems should prioritize this CVE.

Technical summary

The available source material identifies the issue as a memory corruption vulnerability in the Internet Explorer scripting engine. No CVSS score or severity was provided in the supplied corpus, but CISA’s KEV listing indicates active exploitation was known at the time of cataloging.

Defensive priority

High. KEV inclusion makes this a remediation priority even without a supplied CVSS score.

Recommended defensive actions

  • Apply updates per vendor instructions.
  • Verify whether any endpoints, virtual desktops, or application compatibility layers still depend on Internet Explorer components.
  • Prioritize patch deployment and confirm remediation across all affected Windows assets.
  • Use the CISA KEV catalog and the vendor CVE record to track remediation status.

Evidence notes

This debrief is limited to the supplied source corpus and official links. The CVE record and NVD detail page identify the vulnerability as Microsoft Internet Explorer Scripting Engine memory corruption. The CISA Known Exploited Vulnerabilities feed and catalog show the entry date as 2021-11-03 with required action to apply updates per vendor instructions. No additional severity, exploitation chain, or impact details were supplied, so none are asserted here.

Sources and references

Verified primary and authoritative sources

  • CVE-2020-1380 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2020-1380

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2020-1380 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2020-1380

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.