Security readout for executives and security teams
Plain-English summary
CVE-2020-0796 is a critical Windows SMB vulnerability that can let an unauthenticated remote attacker execute code through network requests. Successful exploitation could compromise confidentiality, integrity, and availability. CISA lists it as known exploited, making affected, reachable systems an urgent remediation priority.
Executive priority
Treat as an immediate priority because it combines unauthenticated network attackability, maximum CVSS severity, potentially complete system impact, and confirmed known exploitation. Focus first on reachable affected servers and endpoints, then verify remediation coverage across the remaining estate.
Technical view
The flaw is a memory-safety issue (CWE-119) in Microsoft SMB 3.1.1 request handling. Its CVSS 3.1 score is 10.0: network-accessible, low complexity, requiring neither privileges nor user interaction, with potentially high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited by the supplied evidence to Windows 10 versions 1903 and 1909 across listed architectures, plus Windows Server versions 1903 and 1909 Server Core installations. Risk is highest where affected systems accept SMB traffic from untrusted or broadly reachable networks. Exact vulnerable build ranges are not provided.
Exploitation context
CISA's Known Exploited Vulnerabilities listing supports that CVE-2020-0796 has been exploited in the wild. The supplied sources do not establish current campaign scale, attacker identity, exploitation frequency, or whether any specific organization is targeted.
Researcher notes
The bundle establishes SMB 3.1.1 request handling, CWE-119, critical CVSS characteristics, affected product families, and KEV status. It does not provide exact builds, patch identifiers, root-cause detail, detection signatures, exploit reliability, or campaign evidence. Confirm those details through Microsoft's advisory before operational decisions.
Mitigation direction
- Consult Microsoft's CVE advisory for applicable security updates and vendor-approved mitigations.
- Prioritize remediation of affected systems exposing SMB to untrusted or broadly accessible networks.
- Reduce unnecessary SMB reachability using existing network segmentation and access controls.
- Apply normal change control, backup, and recovery safeguards before production remediation.
Validation and detection
- Inventory the specifically listed Windows 10 and Windows Server versions and architectures.
- Identify which affected systems accept SMB traffic and from which network zones.
- Verify Microsoft-recommended remediation is applied using trusted patch-management records.
- Review security telemetry for suspicious SMB activity, recognizing the bundle provides no detection indicators.
- Reassess reachability and vulnerability status after remediation.
Public sources used
The source record changed after analysis: Material source record changed after analysis.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-119: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-0796 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 10 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H3.96CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2020-0796 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2022-02-10T00:00:00.000Z: CVE-2020-0796 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0796CVE reference, microsoft · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0796CVE reference, CISA-ADP · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.