nvm/.github/THREAT_MODEL.md

nvm Threat Model

Introduction

Threat model analysis assists organizations to proactively identify potential security threats and vulnerabilities, enabling them to develop effective strategies to mitigate these risks before they are exploited by attackers. Furthermore, this often helps to improve the overall security and resilience of a system or application.

The aim of this section is to facilitate the identification of potential security threats and vulnerabilities that may be exploited by adversaries, along with possible outcomes and appropriate mitigations.

Relevant assets and threat actors

The following assets are considered important for the nvm project:

• nvm source code and project documentation
• Underlying nvm dependencies
• nvm development infrastructure
• nvm installed devices including servers

The following threat actors are considered relevant to the nvm application:

• External malicious attackers
• Internal malicious attackers
• Services
• Malicious insider actors
• Third-party libraries

Attack surface for external/internal attackers and services

In threat modeling, an attack surface refers to any possible point of entry that an attacker might use to exploit a system or application. This includes all the paths and interfaces that an attacker may use to access, manipulate or extract sensitive data from a system. By understanding the attack surface, organizations are typically able to identify potential attack vectors and implement appropriate countermeasures to mitigate risks.

In the following diagrams, External Malicious Attacker applies to threat actors who do not yet have direct access to the nvm application and the underlying operating system, while the Internal Malicious Attacker applies to an attacker with access to the device (computer, server), potentially after successfully exploiting a threat from the External Malicious Attacker scenario. Please note that some of the external threats may be also exploitable from internal threats and vice versa.

Fig.: Possible attacks from internal and external threat actors and services

Identified threats

The identified threats against the nvm application are as follows:

Threat ID 1: nvm commands

Overview: The nvm commands and subcommands take user input for handling and executing appropriate functions from the project directory (or any parent directory). When user-controlled inputs are not adequately validated and later passed to the nvm functions as a part of a command, an attacker might be able to execute operating system commands triggered by any parsing functionality.

Possible Outcome: Attacks against nvm commands could lead to unauthorized access to user data or unauthorized access to the device (i.e. laptop or server, depending on where nvm is installed), resulting in loss of user private data stored on the device, among other possibilities.

Recommendation: Input validation should be implemented to prevent attackers from requesting operating system commands. Similarly, secure coding practices ought to be in place to minimize the risk of buffer overflow vulnerabilities.

Threat ID 2: URI scheme

Overview: nvm commands heavily use the Secure HyperText Transfer protocol for nvm related actions. Missing scheme validation for any nvm command might result in file retrieval, enumeration, file overwrite, or path traversal attacks. An example of this could be path validation for nvm_download, among many other possibilities.

Possible Outcome: Security misconfiguration flaws for URI scheme may lead to unauthorized access to user data, as well as data integrity compromises.

Recommendation: Adequate input validation should be implemented to prevent attackers from enumerating, retrieving and writing to application files and paths.

Threat ID 3: Communication channel

Overview: The nvm commands and its subcommands use network protocol to communicate with external services. Insecure communication may allow malicious attackers to perform Man-in-the-Middle attacks in order to manipulate the data sent during the users’ active connection.

Possible Outcome: Usage of plaintext communication protocols, like HTTP could lead to data sniffing and modification through insecure communications channels.

Recommendation: Mitigation countermeasures such as data encryption should be in place to prevent data manipulation via insecure communication channels.

Threat ID 4: Environment variables

Overview: Each nvm installation defines its environment variables, which should be secured from internal malicious attackers, preventing access control attack vectors. Missing stringent restrictions on setting variables, might allow attackers to prepare various targeted attacks against other local users, who use nvm in their user space. For example, Privilege Escalation, Command Injection, as well as many other parser-related attacks.

Possible Outcome: Attacks against environment variables could lead to unauthorized access to the user space, resulting in the loss of user private data and disruptions in service availability.

Recommendation: Adequate hardening of configuration file permissions should be in place for all relevant configuration files, as this provides protection against attackers able to manipulate variables and inject malicious code.

Attack surface for malicious insider actors and third-party libraries

The following diagram summarizes the main possible threats against the nvm project from malicious insider actors and third-party libraries:

Fig.: Possible attacks from insider threat actors and third-party libraries

The identified threats against the nvm project are as follows:

Threat ID 1: Insider threat actor

Overview: An insider threat actor, such as an nvm project contributor or employee with access to the code base, might abuse their role in the organization to modify the nvm application source code. For example, intentionally adding malicious code snippets, clearing logs after being written and/or modifying specific sections of the documentation.

Possible Outcome: Reputation damage, financial losses.

Recommendation: Secure coding practices, code reviews, automated code scanning and separation of duties (i.e. requiring at least two developers to approve any code change) are potentially useful security controls to identify and mitigate vulnerabilities that may be introduced by an insider threat actor.

Threat ID 2: Third-party libraries

Overview: Please note that while nvm does not currently make use of any third-party libraries, this might become an attack vector if that changes in the future. Third-party libraries may introduce potential risks related to maintaining security requirements by third-party vendors. As a result, third-party libraries used by the nvm project, might contain vulnerabilities, such as Buffer Overflows, Format String Vulnerabilities, as well as many other types of weaknesses that, in a worst-case scenario may lead to Remote Code Execution (RCE). Additionally, the maintainer of a third-party dependency might introduce a vulnerability on purpose, or be compromised by an attacker that subsequently introduces vulnerable code.

Possible Outcome: Code vulnerabilities may lead to unauthorized access to user data, loss of user private data, service disruptions and reputation damage.

Recommendation: Third-party libraries should be kept up-to-date, applying patches to address publicly known vulnerabilities in a timely fashion. Monitoring and logging capabilities should also be in place to detect and respond to potential attacks. SLSA compliance may also be considered for further supply chain security hardening.