How to Fix CVE-2014-7169: OS command injection in Bash

WARNING: This vulnerability is on the CISA Known Exploited Vulnerabilities catalog (added 2022-01-28). Federal civilian agencies must remediate by 2022-07-28. Treat it as active exploitation, not theoretical.

What is CVE-2014-7169?

GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of environment variables, which allows remote attackers to write to files or possibly have unknown other impact via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271.

Am I affected?

Run the version check that matches your platform:

# Linux
dpkg -s bash 2>/dev/null | grep -i version
rpm -q bash 2>/dev/null
bash --version 2>/dev/null

Compare what you see against the Affected row above (See the vendor advisory linked below). If your build sits inside that range, you are exposed and should patch.

How to fix CVE-2014-7169

The primary fix is to upgrade Bash to the patched build. Use the commands for your platform below; the patched version listed in the vendor advisory is: See vendor advisory.

Ubuntu / Debian

sudo apt-get update
sudo apt-get install --only-upgrade bash
bash --version 2>/dev/null || dpkg -s bash | grep -i version

RHEL / CentOS / Rocky / AlmaLinux

sudo dnf upgrade --security bash -y
rpm -q bash

SUSE / openSUSE

sudo zypper patch --category security
rpm -q bash

Complete PowerShell remediation script (Windows)

# Fix script for CVE-2014-7169 affecting Bash
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2014-7169-fix-$(Get-Date -Format yyyyMMdd-HHmmss).log"
New-Item -ItemType Directory -Force (Split-Path $LogPath) | Out-Null
Start-Transcript -Path $LogPath -Append

try {
    Write-Host "[1/4] Detecting installed version of Bash"
    $pkg = winget list --id "Bash" 2>$null
    Write-Host $pkg

    Write-Host "[2/4] Backing up configuration"
    $backup = "C:\Backup\Bash-$(Get-Date -Format yyyyMMdd)"
    New-Item -ItemType Directory -Force $backup | Out-Null
    Get-ChildItem "C:\ProgramData\Bash" -ErrorAction SilentlyContinue |
        Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue

    Write-Host "[3/4] Applying upgrade to latest"
    winget upgrade --id "Bash" --silent --accept-source-agreements --accept-package-agreements
    # Fallback: Windows Update for OS-level fixes
    if ($LASTEXITCODE -ne 0) {
        Install-Module -Name PSWindowsUpdate -Force -SkipPublisherCheck -ErrorAction SilentlyContinue
        Import-Module PSWindowsUpdate
        Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
    }

    Write-Host "[4/4] Verifying patched build"
    winget list --id "Bash"
    Write-Host "Fix applied. Reboot if prompted."
    exit 0
} catch {
    Write-Error "Patch failed: $_"
    exit 1
} finally {
    Stop-Transcript
}

Complete Bash remediation script (Linux)

#!/usr/bin/env bash
# Fix script for CVE-2014-7169 affecting Bash
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2014-7169-fix-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG") 2>&1

echo "[1/4] Detecting installed version"
if command -v dpkg >/dev/null; then
    dpkg -s bash 2>/dev/null | grep -i version || echo "bash not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q bash || echo "bash not installed via rpm"
fi

echo "[2/4] Backing up configuration"
BACKUP="/root/backup-cve-2014-7169-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/bash /etc/bash.d /etc/bash.conf; do
    [ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done

echo "[3/4] Applying upgrade (target: latest)"
if command -v apt-get >/dev/null; then
    apt-get update
    apt-get install --only-upgrade -y bash
elif command -v dnf >/dev/null; then
    dnf upgrade --security -y bash
elif command -v yum >/dev/null; then
    yum update -y bash
elif command -v zypper >/dev/null; then
    zypper --non-interactive patch --category security
fi

echo "[4/4] Verifying patched build"
if command -v dpkg >/dev/null; then
    dpkg -s bash 2>/dev/null | grep -i version
elif command -v rpm >/dev/null; then
    rpm -q bash
fi
echo "Done. Restart any running daemons that loaded the old library."

If you can't patch immediately

If you cannot apply the patched version today, restrict exposure with one of the following runnable controls. None replace the patch.

Network restriction (Linux, nftables)

# Block inbound traffic to the affected service from untrusted networks
sudo nft add table inet filter
sudo nft 'add chain inet filter input { type filter hook input priority 0 ; }'
sudo nft 'add rule inet filter input tcp dport {443, 80} ip saddr != 10.0.0.0/8 drop'
sudo nft list ruleset

Reduce attack surface

# bash is a library or shell, not a service. Restart any daemon that links it
# after applying the patch so the new code is actually loaded in memory.
sudo lsof | grep bash | awk '{print $1, $2}' | sort -u
# Then restart each listed process group, or schedule a reboot at the next window.

How to verify the fix worked

# Linux
bash --version 2>/dev/null || dpkg -s bash | grep -i version
rpm -q bash 2>/dev/null || true

# Windows
winget list | findstr /I "bash"
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected: the reported version is at or above the patched build documented in the advisory. Restart any services that loaded the old library (systemctl restart <service> on Linux, restart the Windows service or reboot when prompted). For network appliances, run show version on the device and confirm the build matches the patched release.

Frequently asked questions

Related fixes

Other vulnerabilities in the same area that are worth patching alongside this one:

• How to Fix CVE-2014-6287: Code Injection in Rejetto HTTP File Server (HFS) — Code Injection in Rejetto HTTP File Server (HFS)
• How to Fix CVE-2014-0130: Path Traversal in Rails Ruby on Rails — Path Traversal in Rails Ruby on Rails
• How to Fix CVE-2014-100005: Cross-Site Request Forgery (CSRF) in Dir-600 Firmware , Cross-Site Request Forgery (CSRF) in Dir-600 Firmware
• How to Fix CVE-2014-1812: n/a in n/a , n/a in n/a
• How to Fix CVE-2014-6278: Remote Code Execution in GNU Bash , Remote Code Execution in GNU Bash

Is CVE-2014-7169 actually being exploited?

According to the data sources above, yes, CISA has it listed as actively exploited. Either way, the fix is the same: apply the vendor patch.

Do I need to reboot after patching?

For OS or kernel updates, yes. For most userland packages a systemctl restart <service> is enough. Any process that loaded the old shared library keeps using it until restarted, so when in doubt, reboot.

What is the CVSS score?

9.8 (critical). Refer to the vendor advisory for the exact vector string.

Where is the official advisory?

See the References section at the bottom of this page; the vendor's URL is the authoritative source for affected builds and patched versions.

References

• Official vendor advisory: http://marc.info/?l=bugtraq&m=141577137423233&w=2
• NVD: https://nvd.nist.gov/vuln/detail/CVE-2014-7169
• CISA KEV catalog entry: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• http://packetstormsecurity.com/files/128517/VMware-Security-Advisory-2014-0010.html
• http://www-01.ibm.com/support/docview.wss?uid=ssg1S1004897
• http://www-01.ibm.com/support/docview.wss?uid=swg21685749
• http://www.openwall.com/lists/oss-security/2014/09/24/32

*Written by Sai Kiran Pandrala. Assembled from the official vendor advisory, NVD record, and CISA KEV listing on 2026-05-25. Always confirm against the vendor's advisory before applying changes in production.*