Security readout for executives and security teams
Plain-English summary
This Windows Installer flaw can let an attacker who already has limited local access gain greater control of an affected Windows system. Although its CVSS score is medium, CISA lists it as known exploited, making exposed and unpatched systems a significant operational risk.
Executive priority
Treat remediation as urgent despite the medium CVSS score. Prioritize externally managed endpoints, shared systems, servers, and devices where attackers could obtain local low-privileged access. Require verified patch evidence rather than relying only on deployment reports.
Technical view
CVE-2021-41379 is a local Windows Installer elevation-of-privilege vulnerability classified as CWE-59. The supplied CVSS 3.1 vector indicates low complexity, low privileges required, no user interaction, and high availability impact. Detailed exploit mechanics are not provided in the source bundle.
Likely exposure
Exposure includes listed Windows 10 releases from 1507 through 21H1, Windows 11 21H2, Windows 7, Windows 8.1, and Windows Server 2008 through 2012 R2, including specified Server Core installations. Actual exposure depends on installed security updates.
Exploitation context
CISA’s Known Exploited Vulnerabilities listing supports exploitation in the wild. Exploitation requires local access and low privileges, so this vulnerability is primarily a post-compromise privilege-escalation risk rather than a remotely reachable entry point.
Researcher notes
The source bundle establishes affected releases, CVSS characteristics, CWE classification, a Microsoft patch reference, and KEV status. It does not provide patch identifiers, exploit-chain details, observed threat actors, or reliable indicators of compromise; those claims should not be inferred.
Mitigation direction
- Apply the applicable Microsoft security update identified by the MSRC advisory.
- Prioritize systems accessible to untrusted or low-privileged users.
- Isolate systems that cannot be promptly updated and consult current Microsoft guidance.
- Use endpoint controls to limit unauthorized local code execution.
Validation and detection
- Inventory systems running the affected Windows versions listed in the advisory.
- Confirm the applicable Microsoft security update is installed successfully.
- Identify affected systems lacking updates or reliable patch-status evidence.
- Review endpoint telemetry for unexpected Windows Installer activity from low-privileged contexts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-59: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-41379 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
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C1.83.6microsoftVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
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-2021-41379 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2022-03-03T00:00:00.000Z: CVE-2021-41379 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- Windows Installer Elevation of Privilege VulnerabilityCVE reference, microsoft · vendor-advisory, patch
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-41379CVE reference, CVE · x_refsource_MISC, x_transferred
- https://www.zerodayinitiative.com/advisories/ZDI-21-1308/CVE reference, CVE · x_refsource_MISC, x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-41379CVE 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 Link Resolution Before File Access ('Link Following')
Improper Link Resolution Before File Access ('Link Following') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.