Troubleshooting

Common issues and solutions for scan4all

Overview

This guide covers common issues encountered when using scan4all and their solutions. If you encounter problems not covered here, check the GitHub Discussions.

Installation Issues

libpcap Library Errors

Problem: Error when running scan4all:

libpcap.so.0.8: cannot open shared object file: No such file or directory

Solution 1 - Install libpcap:

Ubuntu/Debian:

sudo apt update
sudo apt install -y libpcap0.8-dev libpcap-dev

CentOS/RHEL:

sudo yum install -yy glibc-devel.x86_64 libpcap

macOS:

brew install libpcap

Solution 2 - Create symbolic link:

If you have a different version of libpcap installed:

# Check what versions are available
ls -all /lib64/libpcap*
# or on some systems
ls -all /usr/lib/x86_64-linux-gnu/libpcap*

# Create symbolic link to required version
sudo ln -s /lib64/libpcap.so.1.9.1 /lib64/libpcap.so.0.8

Docker Environment

Ubuntu container:

apt update && apt install -yy libpcap0.8-dev

CentOS container:

yum install -yy glibc-devel.x86_64

Runtime Issues

Too Many Open Files

Problem: Error during scanning:

too many open files

This occurs when scanning many targets simultaneously.

Check current limits:

ulimit -a
awk '{print $1}' /proc/sys/fs/file-nr

Solution - Increase file descriptor limit:

Temporary (current session):

ulimit -n 819200

Permanent (Linux):

Edit /etc/security/limits.conf:

* soft nofile 819200
* hard nofile 819200

Log out and back in for changes to take effect.

Verify:

ulimit -n

nmap Not Found

Problem: scan4all cannot detect nmap even though it’s installed.

Solution 1 - Disable nmap:

priorityNmap=false ./scan4all -l targets.txt

Solution 2 - Install nmap:

Ubuntu/Debian:

sudo apt install -y nmap

CentOS/RHEL:

sudo yum install -y nmap

macOS:

brew install nmap

Solution 3 - Verify PATH:

which nmap
echo $PATH

Ensure nmap’s location is in your PATH.

nmap Permission Errors

Problem: nmap requires root privileges but PPSSWWDD not set.

Solution - Set root password:

export PPSSWWDD=yourRootPassword
./scan4all -l targets.txt

Be cautious when storing passwords in environment variables. Consider using naabu instead if you cannot provide root access.

Alternative - Use naabu:

priorityNmap=false ./scan4all -l targets.txt

Configuration Issues

Elasticsearch Connection Failed

Problem: Cannot connect to Elasticsearch or results not being stored.

Check Elasticsearch status:

curl http://127.0.0.1:9200/_cluster/health

Solution 1 - Start Elasticsearch:

mkdir -p ~/MyWork/scan4all/logs ~/MyWork/scan4all/data
cd ~/MyWork/scan4all

docker run --restart=always --ulimit nofile=65536:65536 \
  -p 9200:9200 -p 9300:9300 -d --name es \
  -v $PWD/logs:/usr/share/elasticsearch/logs \
  -v $PWD/config/elasticsearch.yml:/usr/share/elasticsearch/config/elasticsearch.yml \
  -v $PWD/config/jvm.options:/usr/share/elasticsearch/config/jvm.options \
  -v $PWD/data:/usr/share/elasticsearch/data \
  hktalent/elasticsearch:7.16.2

Solution 2 - Initialize indices:

./config/initEs.sh

Solution 3 - Check configuration:

Verify config/config.json:

{
  "enableEsSv": true,
  "esUrl": "http://127.0.0.1:9200/%s_index/_doc/%s"
}

Solution 4 - Authentication issues:

If Elasticsearch requires authentication, update config/nuclei_esConfig.yaml:

username: your_username
password: your_password

Config File Not Found

Problem: scan4all cannot find config/config.json.

Solution 1 - Generate default config: Run scan4all once to auto-generate the config directory:

./scan4all -h

Solution 2 - Clone repository:

git clone https://github.com/GhostTroops/scan4all
cd scan4all
go build

Solution 3 - Specify config location: Ensure scan4all is run from the directory containing the config folder, or the config folder is in your home directory.

Scanning Issues

Incomplete Results

Problem: Port scan results are incomplete or missing services.

Possible causes and solutions:

1. Network issues with nmap:

# Switch to naabu
priorityNmap=false ./scan4all -l targets.txt

2. Rate limiting or packet loss:

# Reduce scan rate in config/config.json
"nmap": "nmap ... --min-rate 5000 ..."

3. Firewall blocking:

• Verify target is reachable: ping target
• Check for filtering: nmap -Pn target
• Try from different network location

4. Timeout too aggressive:

# Increase timeout in config/config.json
"nmap": "nmap ... --host-timeout 20m ..."

No Vulnerabilities Found

Problem: scan4all completes but finds no vulnerabilities.

Verification steps:

1. Confirm targets are reachable:

./scan4all -l targets.txt -v -debug

2. Check if ports were discovered:

# View port scan results
http://127.0.0.1:9200/naabu_index/_doc/_search?q=host:"target.com"

3. Verify POC execution:

# Enable nuclei debugging
# Edit config/config.json
{
  "nuclei": {
    "verbose": true,
    "debug": true
  }
}

4. Update POC templates:

# Ensure you're using latest version
go install github.com/GhostTroops/scan4all@latest

Scan Running Too Slow

Problem: Scans take excessively long to complete.

Solutions:

See the Performance Tuning guide for comprehensive optimization strategies.

Quick fixes:

1. Enable nmap (if not already):

export PPSSWWDD=yourRootPassword
priorityNmap=true ./scan4all -l targets.txt

2. Reduce port range:

# Edit config/config.json
{
  "naabu": {
    "TopPorts": "100"
  }
}

3. Disable expensive features:

export EnableSubfinder=false
export ParseSSl=false
./scan4all -l targets.txt

4. Split target list:

split -l 100 targets.txt batch_
for batch in batch_*; do
  ./scan4all -l $batch &
done

High Memory Usage

Problem: scan4all or Elasticsearch consuming excessive memory.

For scan4all:

1. Reduce thread counts:

{
  "nuclei": {"threads": 25},
  "httpx": {"threads": 25}
}

2. Disable caching:

{
  "autoRmCache": "true"
}

3. Scan smaller batches:

# Process targets in smaller groups
head -100 targets.txt > batch1.txt
./scan4all -l batch1.txt

For Elasticsearch:

Adjust JVM heap size in config/jvm.options:

-Xms2g
-Xmx2g

Set heap to 50% of available RAM, but not exceeding 31GB.

Cookie and Authentication Issues

Problem: Authenticated scanning not working with Cookie parameter.

Solution 1 - Verify cookie format:

# Correct format
Cookie='sessionid=abc123; csrftoken=xyz789' ./scan4all -host target.com

# Not this
Cookie='Cookie: sessionid=abc123' ./scan4all -host target.com

Solution 2 - Escape special characters:

Cookie='complex=value%3Dtest%26foo%3Dbar' ./scan4all -host target.com

Solution 3 - Use config file:

Some tools support cookie configuration. Check tool-specific docs.

Output and Results Issues

Cannot Find Results

Problem: Scan completed but results are missing.

Check output locations:

1. Elasticsearch:

# Check all indices
http://127.0.0.1:9200/_cat/indices

# Search specific index
http://127.0.0.1:9200/nuclei_index/_doc/_search?size=100

2. File output:

# Specify output file explicitly
./scan4all -l targets.txt -o results.csv -csv
./scan4all -l targets.txt -json -o results.json

3. Check current directory:

ls -lah *.csv *.json *.txt

Elasticsearch Query Issues

Problem: Cannot query or find specific results in Elasticsearch.

Common query patterns:

By target ID:

http://127.0.0.1:9200/nmap_index/_doc/_search?q=_id:192.168.0.111

By host field:

http://127.0.0.1:9200/nuclei_index/_doc/_search?q=host:"target.com"

All results from index:

http://127.0.0.1:9200/httpx_index/_doc/_search?size=1000

Filter by severity:

http://127.0.0.1:9200/nuclei_index/_doc/_search?q=severity:critical

Integration Issues

log4j-scan Not Working

Problem: log4j vulnerability scanning fails.

Solution - Install log4j-scan:

mkdir -p ~/MyWork
cd ~/MyWork
git clone https://github.com/hktalent/log4j-scan

scan4all will automatically detect and use log4j-scan if it’s in ~/MyWork/log4j-scan.

Verify Python dependencies:

cd ~/MyWork/log4j-scan
pip3 install -r requirements.txt

Subdomain Enumeration Not Working

Problem: EnableSubfinder=true but no subdomains found.

Solution 1 - Verify configuration:

export EnableSubfinder=true
export ParseSSl=true
./scan4all -host target.com -v

Solution 2 - Check API keys:

Some subdomain sources require API keys. Configure in subfinder’s config if needed.

Solution 3 - Be patient:

Subdomain enumeration is very slow. It may take considerable time for results to appear.

Platform-Specific Issues

Windows Issues

Problem: Cache files or nmap paths incorrect on Windows.

Solution 1 - Use Windows path format: The tool should automatically add .exe to nmap, but verify:

{
  "nmap": "nmap.exe ..."
}

Solution 2 - Antivirus interference: Security software may block port scanning. Add exception for scan4all and nmap.

Solution 3 - WinPcap/Npcap: Install Npcap (Windows packet capture library): https://npcap.com/#download

macOS Issues

Problem: Permission denied errors on macOS.

Solution 1 - Grant permissions: macOS may require security permissions for network tools:

• System Preferences → Security & Privacy → Privacy
• Grant Full Disk Access if needed

Solution 2 - Use sudo:

sudo ./scan4all -l targets.txt

Solution 3 - Set PPSSWWDD:

export PPSSWWDD=yourPassword
./scan4all -l targets.txt

Getting Help

Debug Mode

Enable verbose debugging:

./scan4all -l targets.txt -v -debug

Debug mode significantly slows scanning. Use only for troubleshooting.

Useful Diagnostics

Gather information for bug reports:

# Version information
./scan4all -version

# System information
uname -a
go version

# Check dependencies
which nmap
nmap --version

# File limits
ulimit -a

# Network connectivity
ping -c 4 target.com
traceroute target.com

Community Support

GitHub Discussions: https://github.com/GhostTroops/scan4all/discussions

GitHub Issues: https://github.com/GhostTroops/scan4all/issues

Documentation:

• Installation Guide
• Usage Guide
• Parameter Description

When asking for help, include:

1. scan4all version
2. Operating system and version
3. Full error message
4. Command line used (redact sensitive targets)
5. Relevant configuration snippets
6. Steps to reproduce

Common Error Messages

”Target not found”

Cause: Invalid target format or unreachable host.

Solution:

• Verify target format (IP, domain, CIDR, URL)
• Check network connectivity
• Try with -v flag for more details

”No ports found”

Cause: Port scan failed or target has no open ports.

Solution:

• Verify target is online
• Try with priorityNmap=true
• Check firewall rules
• Test with manual nmap scan

”POC execution failed”

Cause: nuclei or vscan encountered an error.

Solution:

• Update to latest version
• Check nuclei templates are present
• Verify target is accessible
• Review error details with -v -debug

”Elasticsearch index error”

Cause: Index not initialized or ES not running.

Solution:

# Check ES status
curl http://127.0.0.1:9200

# Reinitialize indices
./config/initEs.sh

Prevention Best Practices

To avoid common issues:

1. Always check prerequisites:

   • libpcap installed
   • File descriptor limits set
   • Elasticsearch running (if using)
   • nmap installed (if using)

2. Start with verbose mode:

   ./scan4all -l small_test.txt -v
   

3. Test with small target sets first:

   • Verify configuration
   • Confirm connectivity
   • Validate output format

4. Monitor system resources:

   • CPU usage
   • Memory consumption
   • Network bandwidth
   • Disk space

5. Keep tools updated:

   go install github.com/GhostTroops/scan4all@latest
   

Most issues can be resolved by checking the installation prerequisites, reviewing configuration files, and enabling verbose logging.