On October 18, 2022, Sonatype released the 8th annual
State of the Software Supply Chain report [30]. As part
of project quality metrics identification, they built several
machine learning classification models on Scorecard security
practices to understand how well a model based on security
practices could correctly identify projects with known vul-
nerabilities. Their classification models were based on 12,786
Java projects, and they found Code-Review, Binary-Artifacts,
Pinned Dependencies, Branch Protection as important prac-
tices in their classification model.
Our study focuses on understanding whether good secu-
rity practices improve security outcomes, whereas Sonatype
research built models to identify vulnerable projects using
Scorecard data. However, study [20] showed that not all
Scorecard metrics apply to npm and PyPI ecosystems. From
the Sonatype annual report, we could not verify whether all the
metrics applied to Java projects or whether the study removed
noisy metrics from the model’s independent variables.
B. Guidelines and Frameworks:
The Software Component Verification Standard
(SCVS) [14] by OWASP, is a framework to develop a
common set of activities, controls, and security practices that
can help in identifying and reducing risk in a software supply
chain. There are 6control families that contain 87 controls
for different aspects of security verification or processes.
The SCVS has three verification levels, where higher levels
include additional controls.
The Building Security In Maturity Model (BSIMM)
[15] is the result of a multiyear study of real-world software
security initiatives (SSIs). Each year, various firms in differ-
ent industry verticals use the BSIMM to manage their SSI
improvements because the BSIMM report provides a clear
picture of actual practices used by organizations across the
security landscape [16]. The BSIMM is organized as a set of
122 activities, which consist of four domains distributed into
12 practices.
The CNCF Technical Advisory Group (TAG) [17] pub-
lished a series of recommended best practices, tooling rec-
ommendations, and design considerations that can reduce the
likelihood and overall impact of a successful supply chain
attack. They discuss the 5stage of software supply chain se-
curity—securing code, materials, building pipelines, artifacts,
and deployments. The framework proposed 54 practices with
associated risk factors to provide a holistic, end-to-end guide
for organizations and teams.
In response to Section 4 of the President’s Execu-
tive Order (EO) on “Improving the Nation’s Cybersecurity
(14028)” [3], the U.S. National Institute of Standards and
Technology (NIST) improvised the Secure Software Devel-
opment Framework (SSDF) [6]. The framework does not
introduce new practices or define new terminology. Instead,
the framework describes a set of high-level practices based
on established standards [15], [17]–[19] of secure software
development practices.
Supply Chain Levels for Software Artifacts (SLSA) [21]
is a security framework established by industry consensus, a
set of standards and controls to prevent tampering, enhance
the integrity, and also a set of security rules that may be
adopted incrementally. SLSA has four levels, with SLSA 4
representing the ideal end state. The lower levels represent in-
cremental milestones with corresponding incremental integrity
guarantees.
In August 2022, the Cybersecurity and Infrastructure Secu-
rity Agency (CISA) and the National Security Agency (NSA)
released a recommended practice guide on Securing the
Software Supply Chain for Developers [22]. The report
advocated specific frameworks like SLSA and SSDF. The
framework is a roadmap to building a healthy software devel-
opment environment that includes a Software Bill of Materials
(SBOM) for describing software components, active monitor-
ing for vulnerabilities and software supply chain attacks, and
a secure build environment and development team.
Microsoft released the Open Source Software (OSS)
Secure Supply Chain (SSC) Framework [23], which is
a security assurance and risk reduction process focused on
securing how developers consume open source software. The
framework provides security guidance and tools throughout
the developer’s inner-loop and outer-loop processes that have
played a critical role in defending and preventing supply chain
attacks through the consumption of open-source software
across Microsoft. In September 2022, the OpenSSF released
the npm Best Practices Guide [24] to help JavaScript and
TypeScript developers reduce the security risks associated with
using open-source dependencies.
C. Tools
Open Source Insights (OSI) or Deps.dev [25] is a Google-
developed and hosted tool to aid practitioners in grabbing
information about the source code location, package metadata,
licenses, releases, and vulnerabilities of open-source products.
OSI scans millions of open-source packages from different
ecosystems, constructs dependency graphs, and annotates the
metadata in a dashboard. Apart from the package’s metadata,
the OSI dashboard also shows statistics about a package’s
direct or transitive dependencies. On the OSI website, users
can view the vulnerability mapping of a package as well as
the vulnerability mapping with associated dependencies. In
addition to the package metadata, OSI has also incorporated
Scorecard security practices to help understand package secu-
rity practices.
In-toto: A framework that holistically enforces the integrity
of a software supply chain by gathering cryptographically ver-
ifiable information about the chain itself [26], [27]. in-toto
grants the end user the ability to verify the software’s supply
chain from the project’s inception to its deployment. To
achieve this, in-toto requires a project owner to declare
and sign a layout of how the supply chain’s steps must
be carried out and by whom. The concerned parties will
document their actions and produce a cryptographically signed
declaration for each step as they are completed. The link
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