Attackers utilize a technique called session replay to record and repurpose session data (such as cookies, tokens, or network requests) from an authentic user’s active session.
If there is a vulnerability in the session management or API calls of the mobile banking app, an attacker may be able to:
- Take overactive sessions: Intercepting session tokens or other private information sent when a user is in session.
- Replay requests: To change information such as account balances or start illegal activities, these recorded requests are sent back to the bank’s server.
- Authentication Bypass: The session replay attack may be more difficult to detect since it may not require the attacker to go through the authentication procedure because it may reuse legitimate session identifiers.
Session Replay vulnerabilities in mobile apps can have serious implications for financial integrity, especially in the context of banking and fintech applications
- Unauthorized Transactions: Attackers can replay session data to initiate transactions without the user’s consent, potentially transferring funds to their own accounts.
- Balance Manipulation: If session data includes transaction details, attackers could alter balance information, causing discrepancies between the app and the core banking system.
- Data Tampering: Session replay can allow attackers to modify sensitive data, like account numbers, transaction amounts, or even user credentials, without detection.
- Fraudulent Activities: Attackers can exploit replayed sessions to perform fraudulent activities like double-spending, unauthorized bill payments, or fake loan disbursements.
When a session replay attack is detected, swift action is crucial to minimize damage. Here’s a breakdown of the Immediate Actions, Roles & Responsibilities, and Communication Strategy during an incident.
Immediate Actions
- Detection: Check for signs like multiple logins from different IP addresses and unusual access times or locations
- Verification: Token reuse, unauthorized access without credentials are the major indicators for the verification of attack.
- Containment: By terminating suspicious sessions, isolating affected system and blocking of malicious IPs.
- Evidence Preservation: All logs (application, firewall, network) should be securely preserved without any modification.
Roles & Responsibilities
| Role | Responsibilities |
| Incident Response Lead | Coordinates the response, makes decisions, and communicates with stakeholders. |
| Security Analyst | Analyzes logs, identifies attack vectors, and verifies if it’s a session replay attack. |
| IT/Network Team | Implements containment measures, isolates affected systems and supports technical responses. |
| Forensic Investigator | Preserves evidence, analyzes data for root cause analysis. |
| Legal/Compliance Officer | Ensures regulatory compliance, manages legal implications of the breach. |
| Communication Officer | Manages internal and external communications, ensuring consistent messaging. |
Communication Strategy
- Internal Communication: IR team needs to notify relevant departments like IT, legal, senior management with immediate effect.
- External Communication: If sensitive data has been compromised then customers and regulators as per the country law should be notified.
Mitigation Strategies
- End-to-End Encryption: To avoid interception and replay attacks, use end-to-end encryption to encrypt session data while it’s in transit and at rest.
- Session Tokenization: With session tokenization, transactions are conducted using transient, one-time tokens rather than reusable session data.
- Real-Time Anomaly Detection: Use monitoring tools that identify odd trends, including recurring transactions or discrepancies between logs, for real-time anomaly detection.
- Secure API Design: Strong authentication and permission checks should be incorporated into the design of secure APIs used for financial transactions
