CVE-2019-15793

Local permission bypass via wrong namespace translation

Published Apr 23, 2020 · Updated Sep 16, 2024

Incorrect permission handling in Canonical Ubuntu Kernel 5.0 and 5.3 allows local users to bypass discretionary access controls. Several shiftfs paths translate lower-filesystem user and group IDs through init_user_ns instead of the lower superblock's s_user_ns, causing operations to use unintended identities. Exploitation requires local access and a shiftfs lower filesystem outside the initial user namespace; successful access can evade filesystem permission checks.

CVSS severity8.8
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect permission handling in Canonical Ubuntu Kernel 5.0 and 5.3 allows local users to bypass discretionary access controls. Several shiftfs paths translate lower-filesystem user and group IDs through init_user_ns instead of the lower superblock's s_user_ns, causing operations to use unintended identities. Exploitation requires local access and a shiftfs lower filesystem outside the initial user namespace; successful access can evade filesystem permission checks.

The record

CVE
CVE-2019-15793
Published
Apr 23, 2020
Updated
Sep 16, 2024
Vendor
Canonical
Product
Ubuntu Kernel
Classifications
CWE-538, CWE-276, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 23, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=5.0 kernel <5.0.0-35.38
  2. Affected versionversion=5.3.0-11.12 <5.3 kernel* changes=[{"at":"5.3.0-22.24","status":"unaffected"}]

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Canonical · Ubuntu Kernelversion=5.0 kernel <5.0.0-35.38; version=5.3.0-11.12 <5.3 kernel* changes=[{"at":"5.3.0-22.24","status":"unaffected"}]

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-538Insertion of Sensitive Information into Externally-Accessible File or Directory
CWE-276Incorrect Default Permissions
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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