CVE-2019-20044Public exploit

Local privilege escalation via retained saved user ID

Published Feb 24, 2020 · Updated Aug 5, 2024

Privilege escalation in Zsh before 5.8 allows local users to regain privileges dropped with the --no-PRIVILEGED option. When that option is unset, Zsh changes effective IDs but leaves the saved user ID intact, permitting a loaded module that calls setuid() to restore the former effective identity. Exploitation requires existing command execution in a shell that previously held higher privileges, and it can restore those privileges on Linux or macOS.

CVSS severity7.8
High
EPSS probability0.50%
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 Zsh before 5.8 allows local users to regain privileges dropped with the --no-PRIVILEGED option. When that option is unset, Zsh changes effective IDs but leaves the saved user ID intact, permitting a loaded module that calls setuid() to restore the former effective identity. Exploitation requires existing command execution in a shell that previously held higher privileges, and it can restore those privileges on Linux or macOS.

The record

CVE
CVE-2019-20044
Published
Feb 24, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-273, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 24, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-273Improper Check for Dropped Privileges
T1068Exploitation for Privilege Escalation

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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