+6.1 Authenticator Threats

6.1 Authenticator Threats

An attacker who can gain control of an authenticator will often be able to masquerade as the authenticator’s owner. Threats to authenticators can be categorized based on attacks on the types of authentication factors that comprise the authenticator:

“Something you know” may be disclosed to an attacker. For example, the attacker may guess a password. If the authenticator is a shared secret, the attacker could access the CSP or verifier and obtain the secret value or perform a dictionary attack on a hash of that value. An attacker may observe the entry of a PIN or passcode, find a written record or journal entry of a PIN or passcode, or install malicious software (e.g., a keyboard logger) to capture the secret. Additionally, an attacker may determine the secret through offline attacks on a password database maintained by the verifier.

“Something you have” may be lost, damaged, stolen from the owner, or cloned by an attacker. For example, an attacker who gains access to the owner’s computer may copy a software authenticator. A hardware authenticator may be stolen, tampered with, or duplicated. Out-of-band secrets may be intercepted by an attacker and used to authenticate their own session. A subscriber may be socially engineered to provide access to secrets without intentional collusion.

“Something you are” may be replicated, or a false match may occur. For example, an attacker may obtain a copy of the subscriber’s fingerprint and construct a replica.

Subscribers sometimes intentionally collude with attackers, and virtually nothing can be done from an authentication perspective to prevent these attacks. With this caveat in mind, threats to the authenticators used for digital authentication are listed in Table 3 along with some examples.

Table 3. Authenticator threats

Authenticator Threat/Attack Description Examples
Theft An attacker steals a physical authenticator. A hardware cryptographic authenticator is stolen.
    An OTP authenticator is stolen.
    A look-up secret authenticator is stolen.
    A cell phone is stolen.
Duplication The subscriber’s authenticator has been copied with or without their knowledge. Passwords written on paper are disclosed.
    Passwords stored in an electronic file are copied.
    A vulnerability in an insufficiently secure password manager is exploited.
    A software PKI authenticator (i.e., private key) is copied.
    A look-up secret authenticator is copied.
    A counterfeit biometric authenticator is manufactured.
    Exportable cryptographic keys are obtained from a device or cloud-based sync fabric.
Eavesdropping The attacker observes the authenticator secret or authenticator output as the subscriber is authenticating. Passwords are obtained by watching keyboard entries.
    Passwords or authenticator outputs are intercepted by keystroke logging software.
    A PIN is captured from a PIN pad device.
    A hashed password is obtained and used by an attacker for another authentication.
  The attacker intercepts an out-of-band secret by compromising the communication channel. An out-of-band secret is transmitted via unencrypted Wi-Fi and received by the attacker.
Offline Cracking The authenticator is exposed using analytical methods outside of the authentication mechanism. A software PKI authenticator is subjected to a dictionary attack to identify the correct password to decrypt the private key.
Side-Channel Attack The authenticator’s secret is exposed using the physical characteristics of the authenticator. A key is extracted by differential power analysis on a hardware cryptographic authenticator.
    A cryptographic authenticator secret is extracted by analyzing the authenticator’s response time over several attempts.
Phishing or Pharming The authenticator output is captured by fooling the claimant into thinking that the attacker is a verifier or RP. A claimant reveals a password to a website impersonating the verifier.
    A password is revealed by a bank subscriber in response to an email inquiry from a phisher pretending to represent the bank.
    A password is revealed by the claimant at a bogus verifier website reached through DNS spoofing.
Social Engineering The attacker establishes a level of trust with a subscriber to convince them to reveal their authenticator secret or authenticator output. A password is revealed by the subscriber to an officemate asking for the password on behalf of the subscriber’s boss.
    A password is revealed by a subscriber in a telephone inquiry from an attacker masquerading as a system administrator.
    An attacker who has convinced the mobile operator to redirect the victim’s mobile phone to them receives an out-of-band secret sent via SMS.
Authentication Fatigue An attacker causes repeated authentication requests to be sent to the subscriber in an effort to get them to approve. A subscriber approves a fraudulent push-based authentication request to stop repeated requests.
Online Guessing The attacker connects to the verifier online and attempts to guess a valid authenticator output in the context of that verifier. Online dictionary attacks are used to guess passwords.
    Online guessing is used to guess authenticator outputs for an OTP authenticator that is registered to a legitimate subscriber.
Endpoint Compromise Malicious code on the endpoint proxies allows remote access to a connected authenticator without the subscriber’s consent. A cryptographic authenticator connected to the endpoint is used to authenticate remote attackers.
  Malicious code on the endpoint causes authentication to other than the intended verifier. Authentication is performed on behalf of an attacker rather than the subscriber.
    A malicious app on the endpoint reads an out-of-band secret sent via SMS, and the attacker uses the secret to authenticate.
  Malicious code on the endpoint compromises a multi-factor software cryptographic authenticator. Malicious code proxies authenticate or export authenticator keys from the endpoint.
Unauthorized Binding An attacker causes an authenticator under their control to be bound to a subscriber account. An attacker intercepts an authenticator or provisioning key en route to the subscriber.
Latent Keys A decommissioned device retains authentication keys. A device (e.g., laptop computer) is sold without recognition that device-based authentication keys are present and could be used by a new owner.
Proliferation of Keys Transferring device-based authentication keys between devices increases the attack surface. A subscriber copies authentication keys to many devices, possibly some that are not under their direct control, and loses track of where the keys are stored.
Key Transfer Security Authentication keys are transferred between devices through an insufficiently secure cloud service. Access to a cloud service that stores authentication keys requires only single-factor authentication.
    Keys are made available to others through a URL sent via email.
Untrusted Devices Authentication keys are resident on a device that provides insufficient protection. Keys are transferred to an insecure device via the sync fabric.
Insider Threats A trusted insider proves to be untrustworthy. An insider with access to the CSP (e.g., customer support representative) colludes with an attacker to give access to subscriber accounts.

1. Apžvalga

1.1 Nuorodos

1.2 Nustatyti reikalavimai

1.3 Susiję teisės aktai

2. Nustatyti reikalavimai

Reikalavimai

3. Susiję teisės aktai

Teisės aktai
  • NIST -

    EN: Publications of the National Institute of Standards and Technology (NIST), U.S. Department of Commerce, https://www.nist.gov/, from their electronic versions (OSCAL; SP 800-63-4 from its HTML version, https://pages.nist.gov/800-63-4/). Works of NIST employees are not subject to copyright protection in the United States (17 U.S.C. § 105); the OSCAL content is dedicated to the public domain worldwide (CC0 1.0); outside the United States NIST grants the right to reprint its technical series publications in all formats (NIST copyright statement). Republished courtesy of the National Institute of Standards and Technology; each document names its citation. Divided into sections and converted into the GRCA format, the wording unchanged. Only the versions published by NIST are authoritative.

    DE: Veröffentlichungen des National Institute of Standards and Technology (NIST), U.S. Department of Commerce, https://www.nist.gov/, aus ihren elektronischen Fassungen (OSCAL; SP 800-63-4 aus ihrer HTML-Fassung, https://pages.nist.gov/800-63-4/). Werke von NIST-Beschäftigten sind in den USA urheberrechtlich nicht geschützt (17 U.S.C. § 105); die OSCAL-Inhalte sind weltweit gemeinfrei gestellt (CC0 1.0); außerhalb der USA räumt das NIST das Recht ein, seine Technical-Series-Publikationen in allen Formaten neu zu veröffentlichen (Copyright-Hinweis des NIST). „Republished courtesy of the National Institute of Standards and Technology“; jedes Dokument nennt seine Zitierangabe. In Abschnitte aufgeteilt und in das GRCA-Format umgewandelt, der Wortlaut unverändert. Maßgeblich sind allein die vom NIST veröffentlichten Fassungen.