Auth Bypass in Axum with Oracle Db

An Auth Bypass in an Axum application using Oracle Database can occur when session or identity checks are performed in application logic rather than being enforced by a verified database-side mechanism. Axum does not provide built-in authentication; it relies on developer implementations. If credential verification queries Oracle without proper parameterization and session validation, an attacker can manipulate identifiers or tokens to gain unauthorized access.

Consider a login flow where Axum receives a username and password, queries Oracle to retrieve a user record, and then sets a session cookie based only on the presence of a row. If the query uses string concatenation or fails to validate the session state on subsequent requests, an attacker can reuse an arbitrary user ID or session token. For example, a vulnerable Axum handler might construct SQL dynamically:

// WARNING: vulnerable pattern — do not use
let user_id = params.get("user_id").unwrap_or("0");
let query = format!("SELECT username, role FROM users WHERE id = {user_id}");

An attacker providing user_id=1 after authenticating as another user can enumerate or escalate privileges if Oracle returns data for that ID. This bypasses Axum’s route guards because the framework does not automatically enforce ownership or scope checks.

In addition, misconfigured Oracle connection pooling or shared sessions across services can amplify the issue. If Axum uses a single Oracle schema with broad privileges and the application trusts client-supplied identifiers without re-authentication, a BOLA (Broken Level of Authorization) pattern emerges. middleBrick’s LLM/AI Security checks can detect whether prompts or error messages inadvertently expose database structure or admin functions, which can aid an attacker in refining this bypass.

Moreover, if Axum endpoints are unauthenticated or rely on weak API keys, middleBrick’s unauthenticated endpoint detection can flag these routes as high risk. The scanner tests inputs such as modified identifiers or missing authorization headers to confirm whether the bypass is reproducible, aligning with checks for Authentication, BOLA/IDOR, and Input Validation.

Remediation centers on strict parameterization, session validation, and minimizing Oracle privileges. In Axum, use typed extractors and prepared statements to ensure user input never directly interpolates into SQL. Prefer an ORM or query builder that supports bind variables with Oracle types, or use the crate with explicit bind parameters.

Example of a secure Axum handler with Oracle:

use axum::{routing::post, Router};
use oracle::Connection;
use serde::{Deserialize, Serialize};

#[derive(Deserialize)]
struct Login {
    username: String,
    password: String,
}

#[derive(Serialize)]
struct SessionResponse {
    token: String,
    role: String,
}

async fn login(
    form: axum::extract::Form,
    db: axum::extract::State<Connection>
) -> Result<axum::Json<SessionResponse>, (axum::http::StatusCode, String)> {
    let stmt = db
        .prepare("SELECT role, token FROM sessions WHERE username = :1 AND password_hash = DBMS_CRYPTO.HASH(:2, 2)", &[])?;
    let mut rows = stmt.query(&[&form.username as &dyn oracle::ToSql, &form.password as &dyn oracle::ToSql])?;
    if let Some(row) = rows.next()? {
        let role: String = row.get(0)?;
        let token: String = row.get(1)?;
        Ok(axum::Json(SessionResponse { token, role }))
    } else {
        Err((axum::http::StatusCode::UNAUTHORIZED, "Invalid credentials".into()))
    }
}

fn app_state() -> Connection {
    Connection::connect("user", "password", "localhost/orcl").expect("connect")
}

fn main() {
    let state = app_state();
    let app = Router::new()
        .route("/login", post(login))
        .with_state(state);
    // run app omitted
}

This approach binds parameters (`:1`, `:2`) so Oracle treats them as values, not executable SQL. The password should be compared using a server-side hash; avoid storing or comparing plaintext passwords in queries.

For session management, store minimal claims in signed server-side tokens and validate them on each request in Axum middleware, re-verifying against Oracle with parameterized queries. Enforce least privilege in Oracle: the connection user should have read-only access to necessary tables and no administrative rights. middleBrick’s Pro plan supports continuous monitoring to alert if such misconfigurations appear in future scans, and the GitHub Action can gate merges if risk scores degrade.

Finally, test for IDOR by varying identifiers across authenticated requests and confirming Oracle returns data only for the authenticated subject. The CLI tool (middlebrick scan <url>) can validate these fixes by checking whether parameterized queries and proper headers prevent unauthorized data access.