An artifact repository sits at a uniquely trusted position in the software supply chain — everything downstream trusts what it serves, which makes securing the repository itself as important as securing the build pipeline that populates it.
Access control fundamentals
- Write access (publishing new artifacts) should be restricted to authenticated CI pipelines and specific trusted individuals — not broadly available to every developer by default.
- Read access should require authentication where feasible, even for internal-only artifacts, reducing the ability for an attacker with network access to enumerate your internal package namespace.
- Admin access (repository configuration, proxy settings) should be tightly scoped to a small set of people who actually manage the repository's configuration.
Preventing tampering after publish
Once an artifact is published, it should generally be immutable — republishing under the same version identifier with different content is a common vector for supply chain compromise, either malicious or accidental. Configure repositories to reject overwrites of existing versions where your workflow allows it.
Proxy and caching configuration
Many artifact repositories proxy and cache public registries (npm, PyPI, Maven Central) alongside hosting internal packages. Misconfigured scope routing here is exactly what enables dependency confusion attacks — internal package names need to be explicitly routed to your internal repository with no fallback to the public proxy for that namespace.
Vulnerability scanning integration
Artifact repositories increasingly integrate vulnerability scanning directly, flagging known-vulnerable versions as they're pulled or stored. Enabling this at the repository level provides a consistent check independent of whether individual CI pipelines remember to run their own scan.
Retention and cleanup policies
Old, unused artifact versions accumulate over time, some potentially containing known vulnerabilities that were fixed in later versions but never removed. A defined retention policy — archiving or removing old versions past a certain age or usage threshold — reduces the surface of outdated, potentially vulnerable artifacts still technically available for use.
Audit logging
Log and retain who published, downloaded, and modified artifacts, particularly for production-bound packages — this is essential for reconstructing a supply chain incident's actual scope after the fact.