CVE-2021-1647
Exploited in the wild. In CISA KEV since 2021‑11‑03. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
Microsoft Defender Remote Code Execution Vulnerability
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Listed as exploited in the wild since 2021-11-03.
US federal agencies must remediate by 2021-11-17.
Apply updates per vendor instructions.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
39% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
7 events over 1990 days, from the signal feeds we watch.
- OpenVAS check added
- EPSS band changehigh → moderate
- Patch availablerecord updated
- Added to CISA KEV
- Publishedweakness classified
Affected products
- Windows DefenderSecurity Products / endpoint-av-edr
- security essentialsSecurity Products / endpoint-av-edr
- System Center Endpoint ProtectionSecurity Products / endpoint-av-edr
- Microsoft Security EssentialsSecurity Products / endpoint-av-edr
- System Center 2012 R2 Endpoint ProtectionSecurity Products / endpoint-av-edr
- System Center 2012 Endpoint ProtectionSecurity Products / endpoint-av-edr
- Microsoft System Center Endpoint ProtectionOperating Systems / windows
- Microsoft System Center 2012 R2 Endpoint ProtectionOperating Systems / windows
And 5 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored 7.8 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
Sources
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