CAPEC-196: Session Credential Falsification through Forging

MITRE CAPEC attack pattern

Description

An attacker creates a false but functional session credential in order to gain or usurp access to a service. Session credentials allow users to identify themselves to a service after an initial authentication without needing to resend the authentication information (usually a username and password) with every message. If an attacker is able to forge valid session credentials they may be able to bypass authentication or piggy-back off some other authenticated user's session. This attack differs from Reuse of Session IDs and Session Sidejacking attacks in that in the latter attacks an attacker uses a previous or existing credential without modification while, in a forging attack, the attacker must create their own credential, although it may be based on previously observed credentials.

Where this sits in the chain

A finding maps to a weakness (CWE), a weakness is exploited by an attack pattern (CAPEC), and an attack pattern shows up in ATT&CK as observed adversary behaviour. This page is the middle hop.

Weaknesses exploited: CWE-384, CWE-664

ATT&CK techniques: T1134.002, T1134.003, T1606

Prerequisites

• The targeted application must use session credentials to identify legitimate users. Session identifiers that remains unchanged when the privilege levels change. Predictable session identifiers.

Skills required

• Medium: Forge the session credential and reply the request.

Consequences

• Integrity: Modify Data
• Confidentiality: Read Data
• Authorization: Execute Unauthorized Commands
• Accountability, Authentication, Authorization, Non-Repudiation: Gain Privileges
• Access Control, Authorization: Bypass Protection Mechanism

Mitigations

• Implementation: Use session IDs that are difficult to guess or brute-force: One way for the attackers to obtain valid session IDs is by brute-forcing or guessing them. By choosing session identifiers that are sufficiently random, brute-forcing or guessing becomes very difficult.
• Implementation: Regenerate and destroy session identifiers when there is a change in the level of privilege: This ensures that even though a potential victim may have followed a link with a fixated identifier, a new one is issued when the level of privilege changes.

Source

• MITRE CAPEC CAPEC-196