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TI-2021-20533 Aliases CVE-2021-45444GHSA-735j-r9q6-48mw

In zsh before 5.8.1, an attacker can achieve code execution if they control a command…

Priority LOW 38Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

In zsh before 5.8.1, an attacker can achieve code execution if they control a command output inside the prompt, as demonstrated by a %F argument. This occurs because of recursive PROMPT_SUBST expansion.

Why it matters now

EPSS 0.0198 80th percentileScored 2026-11-08
Fix Fixed Red Hat: 1 advisory

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 21

CPEVersionsRoleVendor
cpe:2.3:a:zsh:zsh:*:*:*:*:*:*:*:*before 5.8.1Vulnerablezsh
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*35VulnerableFedoraproject
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*10.15 to before 10.15.7VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020:*:*:*:*:*:*10.15.7 security_update_2020VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*10.15.7 security_update_2020-001VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-005:*:*:*:*:*:*10.15.7 security_update_2020-005VulnerableApple
  • cpe:2.3:a:zsh:zsh:*:*:*:*:*:*:*:* Versions before 5.8.1 Vulnerable ·zsh
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
  • cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:* Versions 10.15 to before 10.15.7 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020:*:*:*:*:*:* Versions 10.15.7 security_update_2020 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:* Versions 10.15.7 security_update_2020-001 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-005:*:*:*:*:*:* Versions 10.15.7 security_update_2020-005 Vulnerable ·Apple
Show 11 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-007:*:*:*:*:*:*10.15.7 security_update_2020-007VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-001:*:*:*:*:*:*10.15.7 security_update_2021-001VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-002:*:*:*:*:*:*10.15.7 security_update_2021-002VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-003:*:*:*:*:*:*10.15.7 security_update_2021-003VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-006:*:*:*:*:*:*10.15.7 security_update_2021-006VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-007:*:*:*:*:*:*10.15.7 security_update_2021-007VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-008:*:*:*:*:*:*10.15.7 security_update_2021-008VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-001:*:*:*:*:*:*10.15.7 security_update_2022-001VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-002:*:*:*:*:*:*10.15.7 security_update_2022-002VulnerableApple
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-003:*:*:*:*:*:*10.15.7 security_update_2022-003VulnerableApple
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*11.0 to before 11.6.6; 12.0.0 to before 12.4VulnerableApple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-007:*:*:*:*:*:* Versions 10.15.7 security_update_2020-007 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-001:*:*:*:*:*:* Versions 10.15.7 security_update_2021-001 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-002:*:*:*:*:*:* Versions 10.15.7 security_update_2021-002 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-003:*:*:*:*:*:* Versions 10.15.7 security_update_2021-003 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-006:*:*:*:*:*:* Versions 10.15.7 security_update_2021-006 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-007:*:*:*:*:*:* Versions 10.15.7 security_update_2021-007 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-008:*:*:*:*:*:* Versions 10.15.7 security_update_2021-008 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-001:*:*:*:*:*:* Versions 10.15.7 security_update_2022-001 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-002:*:*:*:*:*:* Versions 10.15.7 security_update_2022-002 Vulnerable ·Apple
  • cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-003:*:*:*:*:*:* Versions 10.15.7 security_update_2022-003 Vulnerable ·Apple
  • cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* Versions 11.0 to before 11.6.6; 12.0.0 to before 12.4 Vulnerable ·Apple

Remediation

Red Hat 1 advisory

  • RHSA-2022:2120 Released 2022-05-10 · Red Hat rating Moderate
    zsh security update
    • Red Hat Enterprise Linux AppStream (v. 8) zsh-html-5.5.1-9.el8
    • Red Hat Enterprise Linux BaseOS (v. 8) zsh-5.5.1-9.el8

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2022:2120
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2022:2120
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-45444
  2. 2026-10-03 Alias added: GHSA-735j-r9q6-48mw

References

Advisory 12

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences