[KEV] Out-of-Bounds Write in Microsoft Win32k (CVE-2020-1054)
Summary
Out-of-bounds write in Microsoft Win32k (CVE-2020-1054). Successful exploitation can lead to full system takeover. Listed in CISA KEV — actively exploited.
Original description
The description as published by the source.
An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory, aka 'Win32k Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-1143.
Source: CISA Known Exploited Vulnerabilities NVD GitHub Advisory CISA KEV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-1054 has been found in Microsoft Win32k.
Successful exploitation can lead to full system takeover. CVSS score: 7.0/10.
Note: CISA has officially confirmed this is actively exploited in the wild. Treat it with elevated urgency.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Microsoft Win32k CVE-2020-1054" on the vendor's site.
CVE-2020-1054 (Microsoft Win32k) — CWE-787 / CVSS v3 7.0
Attack vector: local / no user interaction
Listed in CISA KEV — actively exploited, treat as top priority.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds write (CWE-787) exists in Microsoft Win32k.
Check the vendor advisory for the affected versions of Microsoft Win32k.
Severity: High (CVSS 7.0/10). Successful exploitation can lead to full system takeover. Listed in CISA KEV — actively exploited in the wild, treat as top priority.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Win32k' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'Win32k' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Win32kを grep し、稼働しているサービス・バージョンを把握する。 -
2Consider incident declaration escalate
Notify SOC / on-callCISA KEV登録済 = 実環境で悪用が観測されている。侵入の兆候があればインシデント対応宣言、無くてもパッチ適用までWAF強化を最優先で。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory NVD
- exploit packetstormsecurity.com
- patch secure@microsoft.com
- patch portal.msrc.microsoft.com
- web cisa.gov
- web github.com