提出 #881015: lin-snow Ech0 5.4.1 Unsalted MD5 Password Hashing in Ech0 Enables Mass Credential Cr

Project address:
[Ech0](https://github.com/lin-snow/Ech0)

## CWE
CWE-327 Use of a Broken or Risky Cryptographic Algorithm

## Vendor of the product(s)
to be confirmed

## Affected product(s)/code base
### Product
Ech0

### Version
5.4.1

## Attack type
- [x] Remote

## Impact
- [x] Information Disclosure
- [x] Escalation of Privileges

## Affected component(s)
internal/util/crypto/crypto.go MD5Encrypt function; internal/service/user/user.go password storage; internal/service/auth/auth.go password verification

## Core vulnerable code path
internal/util/crypto/crypto.go:12-18 MD5Encrypt() → internal/service/user/user.go:113 InitOwner() / user.go:162 Register() → GORM → SQLite → internal/service/auth/auth.go:100 Login() comparison

Core vulnerable code path:

```go
// internal/util/crypto/crypto.go:12-18
func MD5Encrypt(text string) string {
hash := md5.New()
hash.Write([]byte(text))
hashInBytes := hash.Sum(nil)
return hex.EncodeToString(hashInBytes)
}
```

Core vulnerable function: raw MD5 with no salt, no iterations, no memory-hard key derivation. Used in all password paths.

```go
// internal/service/user/user.go:110-113
owner = model.User{
Username: registerDto.Username,
Email: email,
Password: cryptoUtil.MD5Encrypt(registerDto.Password),
IsAdmin: true,
IsOwner: true,
}
```

InitOwner stores the Owner password as unsalted MD5 hash.

## Attack vector(s)
Attacker obtains SQLite database file (data/ech0.db) via backup exposure, misconfigured static file serving, or filesystem access; extracts MD5 password hashes from users table; cracks hashes with hashcat -m 0 using rainbow tables or dictionary attack; authenticates via POST /api/login with cracked credentials to obtain JWT tokens and full administrative access.

## Suggested description of the vulnerability for use in the CVE
Ech0 versions up to 5.4.1 store user passwords using unsalted MD5 hashing. The MD5Encrypt function in internal/util/crypto/crypto.go applies MD5 without any salt or iterative stretching. An attacker who obtains the SQLite database file can trivially recover all user passwords via rainbow tables or GPU-accelerated dictionary attacks, leading to complete account takeover including the Owner/Admin account.

## Discoverer(s)/Credits
Reporter: sumo166
Email: [email protected]
GitHub profile: https://github.com/sumo166

## Reference(s)

## Additional information
The vulnerability was confirmed through source-code audit. All password operations (InitOwner, Register, Login, UpdateUser) use the same unsalted MD5Encrypt function. The SQLite database is stored as a single file at

• ソース: ⚠️ https://github.com/lin-snow/Ech0/issues/314
• ユーザー: summmm (UID 69690)
• 送信: 2026年07月06日 08:58 (2 月 ago)
• モデレーション: 2026年08月20日 15:58 (2 months later)
• ステータス: 承諾済み
• VulDBエントリ: 393736 [lin-snow Ech0 迄 5.4.1 crypto.go MD5Encrypt 弱い暗号化]
• ポイント: 20