Arp Spoofing in Axum with Oracle Db

Arp spoofing is a Layer 2 attack where an adversary sends falsified ARP messages to associate their MAC address with the IP of a legitimate host, typically the database server. When an Axum application communicates with an Oracle Db on the same network segment (or a segment where ARP is not statically controlled), an attacker can intercept, modify, or block traffic between the application and the database. This exposes connection parameters, queries, and potentially authentication material if encryption is not enforced end-to-end.

In an Axum service using Oracle Db, the runtime interaction often involves a connection pool establishing TCP sessions to the Oracle listener on port 1521. If an attacker successfully spoofs the Oracle server’s ARP cache, the Axum application may unknowingly send JDBC or native OCI traffic to the attacker’s machine. Because Axum applications frequently handle structured data and long-lived connections to Oracle Db, the window to capture credentials, SQL statements, or session tokens is significant. Transport Layer Security (TLS) or Oracle Native Network Encryption can mitigate payload exposure, but ARP spoofing still enables session disruption, hijacking, or redirection to a malicious relay.

The risk is compounded when development or staging environments rely on shared or flat networks where static ARP entries are not configured. MiddleBrick’s unauthenticated scan can detect unsafe network exposure patterns and insecure service binding that facilitate ARP spoofing, as part of its BOLA/IDOR and SSRF checks. Even though middleBrick does not fix the issue, its findings highlight the need for host-level network hardening and transport encryption when Axum applications interact with Oracle Db.

Remediation focuses on ensuring that Axum applications establish trusted paths to Oracle Db and avoid reliance on ARP-level trust. Use encrypted connections, validate server identities, and minimize exposure on local networks. Below are concrete practices and code examples tailored for Axum applications using Oracle Db.

1. Enforce encrypted connections with Oracle wallet or SSL/TLS

Configure the Oracle client to require encryption and use a wallet to avoid embedding credentials in code or environment variables. In Axum, manage the connection string to request secure sessions.

// Example connection string for an Axum app using oracle crate
let conn_str = "user=app_user password=**wallet**_(password) connect_string=//dbhost.example:1521/ORCLPDB1";
// In practice, use Oracle Wallet Manager to store credentials and enable SSL/TLS.
// The wallet location is set via sqlnet.ora on the client:
// WALLET_LOCATION = (SOURCE = (METHOD = FILE) (METHOD_DATA = (DIRECTORY = /opt/oracle/wallet)))
// SQLNET.ENCRYPTION_CLIENT = requested
// SQLNET.ENCRYPTION_TYPES_CLIENT = (AES256)

2. Use static ARP entries for critical hosts (defense in depth)

On the host running the Axum runtime, bind the Oracle server IP to its known MAC address. This is a host-level control that complements application-side encryption.

# On the Axum server (Linux example):
sudo ip neigh add 192.168.1.50 lladdr 00:1b:44:11:3a:b7 dev eth0 nud permanent

3. Validate server certificates and avoid trusting all hosts

If using SSL, ensure the Axum app (or underlying Oracle client) verifies the server certificate against a pinned CA. With native Oracle Net encryption, this is managed via sqlnet.ora and cwallet.sso; in code, ensure connection parameters explicitly require verification.

// Example: enforce certificate verification by setting sqlnet.ora parameters:
// SQLNET.ENCRYPTION_CLIENT = requested
// SQLNET.ENCRYPTION_TYPES_CLIENT = (AES256)
// SSL_CLIENT_AUTHENTICATION = TRUE
// The wallet must contain the trusted CA and the server certificate chain.

4. Restrict network exposure and use zero-trust segmentation

Place Axum application servers and Oracle Db in isolated subnets with strict ACLs. Use service meshes or host firewalls to limit who can initiate connections to port 1521. This reduces the attacker surface for ARP spoofing.

# Example iptables rule to allow only the Axum app subnet to reach Oracle:
# sudo iptables -A INPUT -p tcp -s 10.0.2.0/24 --dport 1521 -j ACCEPT
# sudo iptables -A INPUT -p tcp --dport 1521 -j DROP

5. Monitor and rotate credentials via secure channels

Use Oracle profiles and Axum configuration to rotate credentials regularly. Automate secret rotation using vaults and ensure that connection pools re-authenticate over encrypted channels.

-- Oracle profile to limit password lifetime and enable secure authentication:
CREATE PROFILE axum_app_profile LIMIT
  PASSWORD_LIFE_TIME 90
  PASSWORD_REUSE_MAX 5
  PASSWORD_VERIFY_FUNCTION verify_function;

ALTER USER app_user PROFILE axum_app_profile;