CVE-2021-3626

Privilege escalation via unauthenticated localhost mount requests

Published Oct 1, 2021 · Updated Sep 17, 2024

Privilege escalation in Canonical Multipass before 1.7.0 on Windows allows local users to gain host privileges through its control socket. The privileged multipassd daemon accepted mount requests from any process able to reach its unauthenticated localhost TCP socket and mounted attacker-chosen host paths into a guest. A low-privileged local process and an available guest are required; successful abuse exposes host files to guest access under the daemon's authority.

CVSS severity8.8
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Canonical Multipass before 1.7.0 on Windows allows local users to gain host privileges through its control socket. The privileged multipassd daemon accepted mount requests from any process able to reach its unauthenticated localhost TCP socket and mounted attacker-chosen host paths into a guest. A low-privileged local process and an available guest are required; successful abuse exposes host files to guest access under the daemon's authority.

The record

CVE
CVE-2021-3626
Published
Oct 1, 2021
Updated
Sep 17, 2024
Vendor
Canonical
Product
Multipass
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <1.7.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Canonical · Multipassversion=unspecified <1.7.0

Published CVSS scores

8.8CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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