How should security teams prevent path traversal issues in continuous delivery platforms that read local value files?

Why This Matters for Security Teams

Continuous delivery platforms often run with broad filesystem access, so a single path traversal flaw can turn a routine value file lookup into exposure of adjacent repositories, deployment manifests, or cached secrets. That matters because CI/CD is already a high-value path for credential theft and configuration tampering, and NHI compromise often starts with weak file and secret handling. NHI Mgmt Group notes that 96% of organisations store secrets outside secrets managers in vulnerable locations, including code, config files, and CI/CD tools, which makes local file reads especially risky.

Security teams should frame this as an identity and trust boundary issue, not just an input validation bug. If a deployment tool can be influenced to resolve local paths, the attacker is effectively negotiating access to the runner’s filesystem, not just the application’s business logic. NIST’s Cybersecurity Framework 2.0 emphasises governance, access control, and protective handling of assets, which maps directly to this class of issue. Practitioners also need to account for the supply-chain blast radius described in Top 10 NHI Issues, where overexposed machine credentials and automation paths frequently amplify initial mistakes.

In practice, many security teams encounter this only after a build agent has already read a file it should never have been able to see.

How It Works in Practice

The safest pattern is root-bound resolution: the platform should accept a file reference only if the resolved path stays inside a pre-approved directory, and it should enforce that check after normalisation, not before. That means rejecting traversal sequences such as ../, symlink escapes, absolute paths, alternate path encodings, and any platform-specific path trickery that bypasses a simple string comparison. Current guidance suggests treating every file path input as untrusted, even when it comes from a trusted pipeline definition, because attacker-controlled templates and pull requests can still influence the final value.

For continuous delivery tools, the check needs to happen at every resolution point. If one code path reads local values from a working directory, another from a repo checkout, and a third from an artifact cache, all three must apply the same policy. A robust implementation usually includes:

• Canonicalisation using the platform’s real filesystem semantics, not ad hoc string cleanup.
• A strict allowlist of directories the runner may read from.
• Rejection of symlink, junction, and mount-point escapes.
• Short-lived, task-scoped permissions for any secret or file access the pipeline truly needs.
• Logging that records the requested path, resolved path, and whether a policy decision denied access.

Where local value files feed secrets into deployments, that control should be paired with secret minimisation and workload identity discipline. NHI Mgmt Group’s Ultimate Guide to NHIs — The NHI Market highlights how broadly machine identities and secrets are exposed across modern environments, which is why file-read permissions should be treated as high-risk. For implementation alignment, NIST CSF 2.0 and the Zero Trust Architecture guidance both support least privilege, continuous verification, and strong segmentation around workloads.

These controls tend to break down when legacy deployment tooling resolves files before policy enforcement or when symlink handling differs across operating systems and container runtimes.

Common Variations and Edge Cases

Tighter path controls often increase pipeline friction, requiring organisations to balance deployment flexibility against filesystem safety. That tradeoff becomes visible in mono-repos, reusable pipeline templates, and platform-as-code setups where teams expect relative paths to “just work.” Best practice is evolving, but there is no universal standard for this yet: some platforms validate at configuration load time, while others validate only at file open. The safer approach is to validate both.

Edge cases matter. Windows path separators, Unicode normalisation, container bind mounts, and repository submodules can all create unexpected traversal-like behaviour even when the input looks harmless. If a runner can mount external volumes or inherit workspace symlinks, root-bound validation alone may not be enough unless the platform also constrains mount sources and disables unsafe resolution modes. In higher-risk environments, pair this with a read-only working tree, dedicated per-job workspaces, and explicit denial of local file access except where a workflow absolutely requires it.

This is also where governance and visibility matter. NHI Mgmt Group research shows that a large share of organisations still lack full visibility into machine identities and secret sprawl, which means a path traversal issue can expose more than a single config file. Security teams should review whether the platform ever reads local values from directories that also contain tokens, service account material, or cached credentials, and then map those exposures to NIST Cybersecurity Framework 2.0 controls for access control and data protection. The Top 10 NHI Issues research is useful here because it shows how quickly a small control gap can cascade into broader identity compromise.

Related resources from NHI Mgmt Group

• How should security teams prevent path traversal issues when repository names are used to build filesystem paths?
• How should security teams prevent path traversal in Kubernetes storage drivers that use shared multi-tenant exports?
• How should security teams prevent hardcoded secrets from becoming a breach path?
• How do security teams prevent exposed model artifacts from becoming a compromise path?