Affected: Homebrew: pnpm@10

## Summary

pnpm expands `${VAR}` environment placeholders in the `httpProxy` / `httpsProxy` / `noProxy` settings read from a project's `pnpm-workspace.yaml`. Because a project manifest is repository-controlled, a malicious repository that a victim merely clones and runs `pnpm install` in can route all install traffic through an attacker proxy whose hostname or userinfo embeds — and thereby exfiltrates — an environment secret such as `NPM_TOKEN` or `GITHUB_TOKEN`.

This bypasses a trust boundary pnpm deliberately enforces: env-placeholder expansion of request-destination settings is already suppressed for `registry`, `pnprServer`, `registries` and `namedRegistries` when they come from an untrusted project manifest, and the sibling `.npmrc` reader already classifies the proxy keys as request destinations. The manifest-side guard set simply omitted them.

## Impact

An attacker who controls only the contents of a repository's `pnpm-workspace.yaml` — a public repo, a fork, or a supply-chain pull request — can read many values out of the victim's process environment and have them delivered to an attacker-controlled host. No pre-existing access to the victim's store, global config, lockfile, `node_modules`, or environment is required. The secret is exfiltrated during config loading, before any lifecycle script runs.

This turns "I can author a project manifest" into "I read the victim's environment secrets."

## Affected versions

Introduced in pnpm 10.7.0, which added environmen…

pnpm versions 11.0.0 before 11.11.0 and 10.7.0 before 10.34.5 expand ${VAR} environment-variable placeholders in the httpProxy, httpsProxy, and noProxy settings read from a project's pnpm-workspace.yaml. Because the manifest is repository-controlled and the proxy keys were omitted from the request-destination key set that otherwise suppresses placeholder expansion for untrusted manifests (as already done for registry, pnprServer, registries and namedRegistries), an attacker who controls a repository's pnpm-workspace.yaml can cause a victim who clones the repository and runs a pnpm command (e.g. pnpm install) to expand environment secrets such as NPM_TOKEN or GITHUB_TOKEN into a proxy hostname or userinfo and route install traffic — and the corresponding DNS lookups — through an attacker-controlled host. The exfiltration occurs during configuration loading, before any lifecycle script executes. Fixed in pnpm 11.11.0 and 10.34.5.

pnpm versions 11.0.0 before 11.11.0 and 10.7.0 before 10.34.5 expand ${VAR} environment-variable placeholders in the httpProxy, httpsProxy, and noProxy settings read from a project's pnpm-workspace.yaml. Because the manifest is repository-controlled and the proxy keys were omitted from the request-destination key set that otherwise suppresses placeholder expansion for untrusted manifests (as already done for registry, pnprServer, registries and namedRegistries), an attacker who controls a repository's pnpm-workspace.yaml can cause a victim who clones the repository and runs a pnpm command (e.g. pnpm install) to expand environment secrets such as NPM_TOKEN or GITHUB_TOKEN into a proxy hostname or userinfo and route install traffic — and the corresponding DNS lookups — through an attacker-controlled host. The exfiltration occurs during configuration loading, before any lifecycle script executes. Fixed in pnpm 11.11.0 and 10.34.5.