CVE-2021-3769Network attack vector

Shell command execution via double-evaluated branch name

Published Nov 30, 2021 · Updated Aug 3, 2024

Command injection in three Oh My Zsh themes before b3ba9978 allows remote attackers to execute shell commands through a crafted Git branch name. The pygmalion, pygmalion-virtualenv, and refined themes pass Git prompt information containing the branch name to print -P while prompt substitution remains enabled, causing a second evaluation of embedded command substitutions. Exploitation requires one of those themes to be enabled and a user to clone and enter the malicious repository; injected commands then run with that user's shell privileges.

CVSS severity9.8
Critical
EPSS probability0.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in three Oh My Zsh themes before b3ba9978 allows remote attackers to execute shell commands through a crafted Git branch name. The pygmalion, pygmalion-virtualenv, and refined themes pass Git prompt information containing the branch name to print -P while prompt substitution remains enabled, causing a second evaluation of embedded command substitutions. Exploitation requires one of those themes to be enabled and a user to clone and enter the malicious repository; injected commands then run with that user's shell privileges.

The record

CVE
CVE-2021-3769
Published
Nov 30, 2021
Updated
Aug 3, 2024
Vendor
Oh My Zsh
Product
Oh My Zsh
Classifications
CWE-78, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 <b3ba9978

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oh My Zsh · Oh My Zshversion=unspecified <b3ba9978

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
7.5huntr.devCVSS:3.1/AV:N/AC:H/PR:N/UI:R/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.

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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