CVE-2026-0257: PAN-OS GlobalProtect Authentication Bypass — Detection and Remediation Guide

---
title: Suspicious GlobalProtect Authentication Bypass Attempt - CVE-2026-0257
id: a1b2c3d4-5678-90ab-cdef-1234567890ab
status: experimental
description: Detects potential authentication bypass attempts on PAN-OS GlobalProtect interface related to CVE-2026-0257
references:
  - https://www.rapid7.com/blog/post/etr-rapid7-observed-exploitation-of-pan-os-globalprotect-authentication-bypass-vulnerability-cve-2026-0257
  - https://security.paloaltonetworks.com/
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.initial_access
  - attack.t1190
  - cve.2026.0257
logsource:
  category: webserver
  product: pan-os
detection:
  selection:
    cs-method: 'POST'
    c-uri|contains:
      - '/global-protect/login'
      - '/global-protect/portal'
      - '/global-protect/gateway'
    cs-user-agent|contains:
      - 'python-requests'
      - 'curl'
      - 'wget'
  filter_legit:
    cs-user-agent|contains:
      - 'PAN GlobalProtect'
      - 'GlobalProtect'
  condition: selection and not filter_legit
falsepositives:
  - Legitimate vulnerability scanners
  - Security testing tools
level: high
---
title: PAN-OS GlobalProtect Administrative Access Without Authentication
id: b2c3d4e5-6789-01ab-cdef-2345678901bc
status: experimental
description: Detects successful administrative access to GlobalProtect interface without proper authentication sequence
references:
  - https://www.rapid7.com/blog/post/etr-rapid7-observed-exploitation-of-pan-os-globalprotect-authentication-bypass-vulnerability-cve-2026-0257
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.initial_access
  - attack.t1078
  - cve.2026.0257
logsource:
  category: authentication
  product: pan-os
detection:
  selection:
    event_id: '0100035000'  # PAN-OS system login event
    action: 'success'
    object|contains:
      - 'admin'
      - 'superuser'
    src_ip|cidr:
      - '0.0.0.0/0'
  filter_legit:
    src_ip|cidr:
      - '10.0.0.0/8'
      - '172.16.0.0/12'
      - '192.168.0.0/16'
  condition: selection and not filter_legit
falsepositives:
  - Legitimate administrative access from known networks
level: critical
---
title: PAN-OS Configuration Modification Following Suspicious Login
id: c3d4e5f6-7890-12ab-cdef-3456789012cd
status: experimental
description: Detects configuration changes on PAN-OS devices following suspicious authentication patterns indicating potential CVE-2026-0257 exploitation
references:
  - https://www.rapid7.com/blog/post/etr-rapid7-observed-exploitation-of-pan-os-globalprotect-authentication-bypass-vulnerability-cve-2026-0257
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.persistence
  - attack.t1055
  - cve.2026.0257
logsource:
  category: configuration
  product: pan-os
detection:
  selection:
    type: 'CONFIG'
    subtype:
      - 'set'
      - 'edit'
    cmd|contains:
      - 'user'
      - 'admin'
      - 'administrator'
    result: 'success'
  timeframe: 5m
  condition: selection
falsepositives:
  - Legitimate administrative configuration changes
level: medium

// Query for suspicious GlobalProtect authentication patterns
// Look for authentication bypass indicators in PAN-OS logs
let TimeRange = 1h;
let SuspiciousUserAgents = dynamic(['python-requests', 'curl', 'wget', 'powershell']);
let GlobalProtectEndpoints = dynamic(['/global-protect/login', '/global-protect/portal', '/global-protect/gateway']);
Syslog
| where TimeGenerated > ago(TimeRange)
| where DeviceVendor == "Palo Alto Networks"
| where DeviceProduct == "PAN-OS"
| extend LogData = parse_xml(SyslogMessage)
| extend Request = LogData.PAN_THR.THR['@name']
| where Request has_any(GlobalProtectEndpoints)
| extend Method = extract('<@name>([^<]+)</@name>', 1, tostring(LogData))
| extend UserAgent = extract('<@name>([^<]+)</@.name>', 1, tostring(LogData))
| where UserAgent in~ (SuspiciousUserAgents) or isnull(UserAgent)
| project TimeGenerated, DeviceAddress, SourceIP, UserAgent, Request, Method, SyslogMessage
| order by TimeGenerated desc


// Query for administrative login attempts to GlobalProtect without preceding authentication
let TimeRange = 6h;
CommonSecurityLog
| where TimeGenerated > ago(TimeRange)
| where DeviceVendor == "Palo Alto Networks"
| where DeviceProduct == "PAN-OS"
| where RequestURL contains "global-protect"
| where Activity has_any("login", "authenticate", "admin")
| where SentBytes < 1000  // Potential bypass attempts often involve minimal payloads
| summarize Count=count() by SourceIP, DeviceAddress, RequestURL, Activity, bin(TimeGenerated, 5m)
| where Count > 5
| project TimeGenerated, SourceIP, DeviceAddress, RequestURL, Activity, Count
| order by TimeGenerated desc

-- Hunt for suspicious PAN-OS configuration changes indicating potential exploitation
-- This query targets system logs and configuration files on PAN-OS devices

SELECT * FROM glob(
  globs='/var/log/panos/*.log',
  accessor='file'
)
WHERE 
  Name =~ 'system.log' 
  OR Name =~ 'auth.log'
  OR Name =~ 'globalprotect.log'

-- Query for recent administrative access patterns
LET RecentAdminAccess = SELECT *
FROM foreach(
  row={
    SELECT FullPath FROM glob(
      globs='/var/log/panos/traffic.log',
      accessor='file'
    )
  },
  query={
    SELECT Line, FullPath, Mtime
    FROM parse_lines(
      data=read_file(filename=FullPath, length=10000000)
    )
    WHERE 
      Line =~ 'admin'
      AND Line =~ 'global-protect'
      AND Mtime > now() - 24h
  }
)

-- Query for suspicious process executions on PAN-OS
SELECT Pid, Name, CommandLine, Exe, Username, CreateTime
FROM pslist()
WHERE 
  Name =~ 'https'
  OR Name =~ 'sshd'
  AND CommandLine =~ 'global-protect'
  AND CreateTime > now() - 24h

#!/bin/bash
# PAN-OS CVE-2026-0257 Remediation and Verification Script
# This script helps identify vulnerable PAN-OS versions and provides guidance for remediation

set -e

# Color codes for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

echo "=================================="
echo "PAN-OS CVE-2026-0257 Remediation Script"
echo "=================================="
echo ""

# Function to check current PAN-OS version
check_panos_version() {
    echo -e "${YELLOW}[+] Checking current PAN-OS version...${NC}"
    if command -v sw_version &> /dev/null; then
        CURRENT_VERSION=$(sw_version | grep -oP 'PAN-OS \K[0-9]+\.[0-9]+\.[0-9]+')
        echo -e "Current PAN-OS version: ${GREEN}$CURRENT_VERSION${NC}"
        return 0
    else
        echo -e "${RED}[-] Unable to determine PAN-OS version. Please run this script directly on the PAN-OS device.${NC}"
        return 1
    fi
}

# Function to check if version is vulnerable
check_vulnerability() {
    local version=$1
    local major=$(echo $version | cut -d. -f1)
    local minor=$(echo $version | cut -d. -f2)
    local patch=$(echo $version | cut -d. -f3)
    
    # Vulnerable versions based on advisory
    # PAN-OS 10.2.x < 10.2.9-h1
    # PAN-OS 11.0.x < 11.0.5-h1
    # PAN-OS 11.1.x < 11.1.3-h1
    # PAN-OS 11.2.x < 11.2.1-h1
    
    VULNERABLE=false
    
    case "$major.$minor" in
        "10.2")
            if [[ "$patch" < "9" ]]; then
                VULNERABLE=true
                RECOMMENDED_VERSION="10.2.9-h1"
            fi
            ;;
        "11.0")
            if [[ "$patch" < "5" ]]; then
                VULNERABLE=true
                RECOMMENDED_VERSION="11.0.5-h1"
            fi
            ;;
        "11.1")
            if [[ "$patch" < "3" ]]; then
                VULNERABLE=true
                RECOMMENDED_VERSION="11.1.3-h1"
            fi
            ;;
        "11.2")
            if [[ "$patch" < "1" ]]; then
                VULNERABLE=true
                RECOMMENDED_VERSION="11.2.1-h1"
            fi
            ;;
        *)
            echo -e "${RED}[-] Version $major.$minor.x not in vulnerability assessment scope${NC}"
            ;;
    esac
    
    if [ "$VULNERABLE" = true ]; then
        echo -e "${RED}[!] THIS SYSTEM IS VULNERABLE TO CVE-2026-0257${NC}"
        echo -e "${YELLOW}[*] Recommended minimum version: $RECOMMENDED_VERSION${NC}"
        return 1
    else
        echo -e "${GREEN}[+] This system is NOT vulnerable to CVE-2026-0257${NC}"
        return 0
    fi
}

# Function to implement temporary mitigation
apply_mitigation() {
    echo ""
    echo -e "${YELLOW}[+] Applying temporary mitigation measures...${NC}"
    
    # Disable GlobalProtect service if not required
    echo -e "${YELLOW}[*] Checking GlobalProtect service status...${NC}"
    
    # Note: Actual commands would depend on PAN-OS CLI interface
    # This is a template showing what would be done
    
    echo -e "${YELLOW}[*] Recommend implementing the following mitigations:${NC}"
    echo "1. Restrict access to GlobalProtect interfaces to trusted IP ranges"
    echo "2. Enable MFA for all GlobalProtect authentication"
    echo "3. Review and limit administrative interface exposure"
    echo "4. Monitor logs for suspicious authentication attempts"
    
    # Sample CLI commands for PAN-OS
    echo ""
    echo -e "${YELLOW}[*] Sample mitigation commands (to be executed via CLI):${NC}"
    echo "set deviceconfig setting management global-protect enable yes"
    echo "set deviceconfig setting management global-protect restrict-access <trusted-ips>"
    
    return 0
}

# Function to check for signs of exploitation
check_exploitation() {
    echo ""
    echo -e "${YELLOW}[+] Checking for signs of exploitation...${NC}"
    
    # Check for suspicious log entries
    if [ -f "/var/log/panos/system.log" ]; then
        SUSPICIOUS_COUNT=$(grep -c "global-protect.*admin" /var/log/panos/system.log 2>/dev/null || echo "0")
        if [ "$SUSPICIOUS_COUNT" -gt 0 ]; then
            echo -e "${RED}[!] Found $SUSPICIOUS_COUNT potentially suspicious log entries${NC}"
            echo "Please review /var/log/panos/system.log for unusual authentication patterns"
        else
            echo -e "${GREEN}[+] No suspicious log entries found${NC}"
        fi
    fi
    
    # Check for unknown administrative accounts
    echo -e "${YELLOW}[*] Reviewing administrative accounts...${NC}"
    echo "Please manually verify all administrative accounts are legitimate"
    
    return 0
}

# Main execution
main() {
    if check_panos_version; then
        check_vulnerability "$CURRENT_VERSION"
        if [ $? -ne 0 ]; then
            apply_mitigation
            check_exploitation
            
            echo ""
            echo -e "${RED}==================================${NC}"
            echo -e "${RED}[!] CRITICAL ACTION REQUIRED${NC}"
            echo -e "${RED}==================================${NC}"
            echo "1. Immediately apply the relevant hotfix from Palo Alto Networks"
            echo "2. Refer to official advisory: https://security.paloaltonetworks.com/CVE-2026-0257"
            echo "3. Implement the temporary mitigations until patching is complete"
            echo "4. Rotate all administrative credentials after patching"
            echo "5. Conduct thorough log analysis for signs of compromise"
            echo ""
        fi
    fi
    
    echo "Script execution completed."
}

main "$@"