Security readout for executives and security teams
Plain-English summary
Canonical Multipass for macOS installed its application directory with the wrong owner in version 1.7.0. A local low-privileged user could potentially abuse that trust boundary, with the CVSS record rating confidentiality, integrity, and availability impact as high. The issue is reported fixed in 1.7.2.
Executive priority
Treat this as a high-priority endpoint and developer-workstation hygiene issue, especially where macOS machines are shared or used for privileged build workflows. It is not supported as internet-remote or actively exploited by the provided sources.
Technical view
CVE-2021-3747 is a CWE-732 incorrect permission assignment in the macOS version of Canonical Multipass. The CVSS 3.1 vector is local, low complexity, low privileges required, no user interaction, and changed scope. The provided sources identify Multipass 1.7.0 as affected and 1.7.2 as fixed.
Likely exposure
Exposure is limited to macOS systems running Canonical Multipass version 1.7.0, or 1.7 as represented in the affected product data. Organizations using Multipass only on Linux or Windows are not identified as affected by the provided bundle.
Exploitation context
The CVE is not listed as KEV in the provided data, and the sources do not state active exploitation. The risk model is local: an attacker would already need low-privileged access to the macOS host.
Researcher notes
The public bundle gives the affected product, fixed version, CWE, and CVSS vector, but not the exact directory path or exploit mechanics. Avoid assuming broader platform impact or exploitation until Canonical or another cited source states it.
Mitigation direction
- Upgrade macOS Multipass installations to version 1.7.2 or later.
- Inventory developer and build machines for Multipass 1.7.0 or 1.7 installs.
- Prioritize shared macOS hosts or endpoints with multiple local users.
- Check Canonical guidance for any additional vendor-specific cleanup steps.
Validation and detection
- Confirm whether Multipass is installed on managed macOS endpoints.
- Record the installed Multipass version on each identified host.
- Verify remediated systems are running version 1.7.2 or later.
- Compare application directory ownership with vendor guidance or a known-good fixed install.
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-732: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupCVE-2021-3747 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
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/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.
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:C/C:H/I:H/A:H26Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/canonical/multipass/issues/2261CVE reference · x_refsource_MISC
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.
Incorrect Permission Assignment for Critical Resource
Incorrect Permission Assignment for Critical Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.