Transport Layer Security (TLS) provides a secure channel between systems communicating over the internet by encrypting the data sent between them.
HTTPS uses TLS on top of HTTP to build a secure communication channel.
This secure protocol is essential for the confidentiality and integrity of the communication during supply chain operations. This includes fetching
dependencies with the Swift Package Manager (swift package resolve, swift package update, etc.).
The Package.swift manifest file defines the dependencies of a project for the Swift Package Manager. When declaring a package
dependency, a URL to its Git repository is specified.
Using the unencrypted HTTP protocol for package dependencies is not generally recommended. It makes the build process vulnerable to
man-in-the-middle attacks, which could lead to using compromised dependencies. It is important that HTTPS is used for these repository URIs
instead.
What is the potential impact
Man-in-the-middle (MitM) attacks
An attacker can intercept the communication between the client and server, allowing them to modify the data being transmitted.
Supply chain attacks
Without the verification provided by TLS certificates, attackers can redirect package requests to malicious servers that mimic legitimate package
repositories.
For example, an attacker could inject malicious code into a package being downloaded, which would compromise the security of the application being
built.
This can cause further security breaches inside the organization, but will also affect clients if the malicious code gets added to any products, as
a part of a production dependency or as code generated by a tampered development dependency.
Distributing code that (unintentionally) contains backdoors or malware can lead to widespread security vulnerabilities, reputational damage, and
potential legal liabilities.
Credential exposure
Sensitive information, such as API keys or user credentials used to interact with the remote package repository, could be exposed during
transmission. This could lead to unauthorized access to the application or its data.
