Gogs Zero-Day Unauthenticated RCE Vulnerability: Detection and Mitigation Guide

---
title: Gogs Web Service Spawning Shell Processes
id: 9f8e7d6c-5b4a-3c2d-1e0f-9a8b7c6d5e4f
status: experimental
description: Detects Gogs web service spawning shell processes, indicative of RCE exploitation
references:
  - https://www.bleepingcomputer.com/news/security/new-gogs-zero-day-flaw-lets-hackers-get-remote-code-execution/
author: Security Arsenal
date: 2025/04/11
tags:
  - attack.initial_access
  - attack.execution
  - attack.t1059
logsource:
  category: process_creation
  product: linux
detection:
  selection:
    ParentImage|endswith: '/gogs'
    Image|endswith:
      - '/bash'
      - '/sh'
      - '/zsh'
      - '/python'
      - '/perl'
  condition: selection
falsepositives:
  - Legitimate administrative use
  - Authorized plugin execution
level: critical
---
title: Suspicious Outbound Connections from Gogs Process
id: 1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects outbound network connections initiated by Gogs process, potential C2 activity
references:
  - https://www.bleepingcomputer.com/news/security/new-gogs-zero-day-flaw-lets-hackers-get-remote-code-execution/
author: Security Arsenal
date: 2025/04/11
tags:
  - attack.command_and_control
  - attack.t1071
logsource:
  category: network_connection
  product: linux
detection:
  selection:
    Image|endswith: '/gogs'
    Initiated: true
    DestinationPort|not:
      - 22
      - 80
      - 443
  condition: selection
falsepositives:
  - Legitimate webhook notifications
  - Git clone operations to non-standard ports
level: high
---
title: Suspicious File Creation in Gogs Directories
id: 2b3c4d5e-6f7a-8b9c-0d1e-2f3a4b5c6d7e
status: experimental
description: Detects creation of suspicious executable files within Gogs installation directories
references:
  - https://www.bleepingcomputer.com/news/security/new-gogs-zero-day-flaw-lets-hackers-get-remote-code-execution/
author: Security Arsenal
date: 2025/04/11
tags:
  - attack.persistence
  - attack.t1543
logsource:
  category: file_creation
  product: linux
detection:
  selection:
    TargetFilename|contains:
      - '/gogs/'
      - '/gogs-repositories/'
    TargetFilename|endswith:
      - '.sh'
      - '.py'
      - '.pl'
      - '.elf'
  condition: selection
falsepositives:
  - Legitimate plugin installation
  - Authorized custom hooks
level: medium

// Detect Gogs process spawning shell commands
DeviceProcessEvents
| where InitiatingProcessFileName == "gogs"
| where FileName in~ ("bash", "sh", "zsh", "python", "python3", "perl")
| project Timestamp, DeviceName, AccountName, FileName, ProcessCommandLine, InitiatingProcessFileName
| order by Timestamp desc

// Detect outbound network connections from Gogs process
DeviceNetworkEvents
| where InitiatingProcessFileName == "gogs"
| where ActionType == "ConnectionSuccess"
| where RemotePort !in (22, 80, 443)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName
| order by Timestamp desc

// Detect file creation in Gogs directories with suspicious extensions
DeviceFileEvents
| where InitiatingProcessFileName == "gogs"
| where FolderPath contains @"gogs" or FolderPath contains @"gogs-repositories"
| where FileName has_any (@".sh", @".py", @".pl", @".elf")
| project Timestamp, DeviceName, FileName, FolderPath, SHA256, InitiatingProcessFileName
| order by Timestamp desc

-- Hunt for suspicious child processes spawned by Gogs
SELECT Pid, Name, CommandLine, Exe, Username, ParentPid, CreateTime
FROM pslist()
WHERE Parent.Name =~ "gogs"
   AND Name IN ("bash", "sh", "zsh", "python", "python3", "perl")

-- Hunt for suspicious network connections from Gogs process
SELECT Pid, RemoteAddress, RemotePort, State, Family, Protocol
FROM netstat()
WHERE Pid IN (SELECT Pid FROM pslist() WHERE Name =~ "gogs")
   AND RemotePort NOT IN (22, 80, 443)
   AND State =~ "ESTABLISHED"

-- Hunt for recently created suspicious files in Gogs directories
SELECT FullPath, Size, Mtime, Atime, Btime, Mode
FROM glob(globs="/**/gogs/**/*.sh", root="/")
   OR glob(globs="/**/gogs/**/*.py", root="/")
   OR glob(globs="/**/gogs/**/*.pl", root="/")
   OR glob(globs="/**/gogs/**/*.elf", root="/")
WHERE Mtime < timestamp(now="-1d")

#!/bin/bash
# Gogs Zero-Day Remediation Script
# This script checks for signs of compromise and applies mitigations

LOG_FILE="/var/log/gogs_remediation_$(date +%Y%m%d_%H%M%S).log"
exec > >(tee -a "$LOG_FILE") 2>&1

echo "=== Gogs Zero-Day Remediation Script ==="
echo "Started: $(date)"

# Check if Gogs is running
if pgrep -x "gogs" > /dev/null; then
    echo "[!] Gogs process detected running on this system"
    GOGS_PID=$(pgrep -x "gogs")
    echo "[+] Gogs PID: $GOGS_PID"
else
    echo "[+] Gogs process not detected - skipping process checks"
    exit 0
fi

# Check for suspicious child processes
echo "[*] Checking for suspicious child processes..."
suspicious_procs=$(ps -eo pid,ppid,cmd | awk -v pid="$GOGS_PID" '$2 == pid && ($3 ~ /bash|sh|zsh|python|perl/) {print}')
if [ ! -z "$suspicious_procs" ]; then
    echo "[!] Suspicious child processes detected:"
    echo "$suspicious_procs"
else
    echo "[+] No suspicious child processes detected"
fi

# Check for outbound network connections
echo "[*] Checking for suspicious outbound connections..."
suspicious_conns=$(netstat -tapn 2>/dev/null | awk -v pid="$GOGS_PID" '$7 ~ pid {print}' | grep -v "ESTABLISHED" | grep -E ":22 |:80 |:443 ")
if [ ! -z "$suspicious_conns" ]; then
    echo "[!] Suspicious outbound connections detected:"
    echo "$suspicious_conns"
else
    echo "[+] No suspicious outbound connections detected"
fi

# Locate Gogs installation directory
GOGS_DIR=$(find / -name "gogs" -type d 2>/dev/null | head -n 1)
if [ ! -z "$GOGS_DIR" ]; then
    echo "[+] Found Gogs directory: $GOGS_DIR"
    
    # Check for recently modified suspicious files
    echo "[*] Checking for recently modified suspicious files..."
    find "$GOGS_DIR" -type f \( -name "*.sh" -o -name "*.py" -o -name "*.pl" -o -name "*.elf" \) -mtime -1 -ls
    
    # Backup the current Gogs configuration
    echo "[*] Backing up Gogs configuration..."
    if [ -f "$GOGS_DIR/conf/app.ini" ]; then
        cp "$GOGS_DIR/conf/app.ini" "$GOGS_DIR/conf/app.ini.backup.$(date +%Y%m%d_%H%M%S)"
        echo "[+] Configuration backed up"
    fi
else
    echo "[!] Could not locate Gogs installation directory"
fi

# Check system for indicators of compromise
echo "[*] Checking for webshells in web directories..."
find /var/www /home -type f -name "*.php" -o -name "*.jsp" -o -name "*.jspx" | xargs grep -l "eval\|base64_decode\|system\|exec\|shell_exec\|passthru" 2>/dev/null

# Recommendations for mitigation
echo ""
echo "=== Recommended Mitigation Steps ==="
echo "1. If Internet-facing, immediately isolate the Gogs server from external networks"
echo "2. Implement IP whitelisting to restrict access to trusted sources only"
echo "3. Monitor for official vendor security advisories and patches"
echo "4. If compromise is suspected, initiate incident response procedures"
echo "5. Consider migrating to an alternative Git service (e.g., GitLab CE, Gitea) if patch is delayed"
echo "6. Review and rotate all credentials stored in Gogs repositories"
echo ""
echo "Remediation script completed: $(date)"