Adversaries implant malicious code in open source software (OSS) libraries to have it widely distributed, as OSS is commonly downloaded by developers and other users to incorporate into software development projects. The adversary can have a particular system in mind to target, or the implantation can be the first stage of follow-on attacks on many systems.
Low
High

1
Explore
[Determine the relevant open-source code project to target] The adversary will make the selection based on various criteria:
The open-source code currently in use on a selected target system.
The depth in the dependency graph of the open source code in relationship to other code bases in use on the target system. Choosing an OSS lower in the graph decreases the probability of discovery, but also decreases the scope of its use within the target system.
The programming language in which the open source code is implemented. Different languages present different opportunities for using known software weaknesses.
The quality of processes in place to make a contribution. For instance, some contribution sites use static and dynamic analysis tools, which could increase the probability of discovery.
The security requirements necessary to make a contribution. For instance, is the ownership lax allowing unsigned commits or anonymous users.

2
Experiment
[Develop a plan for malicious contribution] The adversary develops a plan to contribute malicious code, taking the following into consideration:
The adversary will probably avoid easy-to-find software weaknesses, especially ones that static and dynamic analysis tools are likely to discover.
Common coding errors or missing edge cases of the algorithm, which can be explained away as being accidental, if discovered, will be preferred by the adversary.
Sometimes no identity is required to make a contribution. Other options are to steal an existing identity or create one. When creating a new identity, strike a balance between too little or too much detail. Using an stolen identity could cause a notification to be sent to the actual user.

3
Exploit
[Execute the plan for malicious contribution] Write the code to be contributed based on the plan and then submit the contribution. Multiple commits, possibly using multiple identities, will help obscure the attack. Monitor the contribution site to try to determine if the code has been uploaded to the target system.

Access to the open source code base being used by the manufacturer in a system being developed or currently deployed at a victim location.

Advanced knowledge about the inclusion and specific usage of an open source code project within system being targeted for infiltration.

An adversary with access to an open source code project introduces a hard-to-find bug in the software that allows under very specific conditions for encryption to be disabled on data streams. The adversary commits the change to the code which is picked up by a manufacturer who develops VPN software. It is eventually deployed at the victim's location where the very specific conditions are met giving the adversary the ability to sniff plaintext traffic thought to be encrypted. This can provide to the adversary access to sensitive data of the victim.

1195.001
Supply Chain Compromise: Software Dependencies and Development Tools

CAPEC Content Team
The MITRE Corporation
2014-06-23

CAPEC Content Team
The MITRE Corporation
2015-11-09
Updated Related_Attack_Patterns, Typical_Likelihood_of_Exploit

CAPEC Content Team
The MITRE Corporation
2018-07-31
Updated Related_Attack_Patterns

CAPEC Content Team
The MITRE Corporation
2019-09-30
Updated Description, Execution_Flow, Related_Attack_Patterns

CAPEC Content Team
The MITRE Corporation
2021-06-24
Updated @Name, Description, Example_Instances, Execution_Flow, Related_Attack_Patterns

CAPEC Content Team
The MITRE Corporation
2022-09-29
Updated Execution_Flow, Taxonomy_Mappings

CAPEC Content Team
The MITRE Corporation
2023-01-24
Updated Related_Weaknesses

Open Source Libraries Altered