CVE-2020-36394Public exploit

Arbitrary filesystem quota changes via FUSE mount

Published Jun 22, 2021 · Updated Aug 4, 2024

Improper filesystem selection in Linux-PAM pam_setquota before 2020-05-29 allows local users to redirect quota changes. pam_sm_open_session accepts an exact home-directory mount and trusts its source-device name, which an unprivileged user can control through a FUSE mount. Exploitation requires pam_setquota during login and a FUSE filesystem over the user's home directory; the privileged module then applies quota changes to the selected block device.

CVSS severity7.0
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper filesystem selection in Linux-PAM pam_setquota before 2020-05-29 allows local users to redirect quota changes. pam_sm_open_session accepts an exact home-directory mount and trusts its source-device name, which an unprivileged user can control through a FUSE mount. Exploitation requires pam_setquota during login and a FUSE filesystem over the user's home directory; the privileged module then applies quota changes to the selected block device.

The record

CVE
CVE-2020-36394
Published
Jun 22, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1548.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.9NIST NVDAV:L/AC:M/Au:N/C:C/I:C/A:C
7.0NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/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 exploitPublished

Weakness, pattern, technique

T1548.001Setuid and Setgid

Public exploit references

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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