Описание
pnpm no-script global cache poisoning via overrides / ignore-scripts evasion
Summary
pnpm seems to mishandle overrides and global cache:
- Overrides from one workspace leak into npm metadata saved in global cache
- npm metadata from global cache affects other workspaces
- installs by default don't revalidate the data (including on first lockfile generation)
This can make workspace A (even running with ignore-scripts=true) posion global cache and execute scripts in workspace B
Users generally expect ignore-scripts to be sufficient to prevent immediate code execution on install (e.g. when the tree is just repacked/bundled without executing it).
Here, that expectation is broken
Details
See PoC.
In it, overrides from a single run of A get leaked into e.g. ~/Library/Caches/pnpm/metadata/registry.npmjs.org/rimraf.json and persistently affect all other projects using the cache
PoC
Postinstall code used in PoC is benign and can be inspected in https://www.npmjs.com/package/ponyhooves?activeTab=code, it's just a console.log
- Remove store and cache
On mac:
rm -rf ~/Library/Caches/pnpm ~/Library/pnpm/storeThis step is not required in general, but we'll be using a popular package for PoC that's likely cached - Create
A/package.json:{ "name": "A", "pnpm": { "overrides": { "rimraf>glob": "npm:ponyhooves@1" } }, "dependencies": { "rimraf": "6.0.1" } }Install it withpnpm i --ignore-scripts(the flag is not required, but the point of the demo is to show that it doesn't help) - Create
B/package.json:{ "name": "B", "dependencies": { "rimraf": "6.0.1" } }Install it withpnpm i
Result:
Also, that code got leaked into another project and it's lockfile now!
Impact
Global state integrity is lost via operations that one would expect to be secure, enabling subsequently running arbitrary code execution on installs
As a work-around, use separate cache and store dirs in each workspace
Пакеты
pnpm
< 9.15.0
9.15.0
Связанные уязвимости
The package manager pnpm prior to version 9.15.0 seems to mishandle overrides and global cache: Overrides from one workspace leak into npm metadata saved in global cache; npm metadata from global cache affects other workspaces; and installs by default don't revalidate the data (including on first lockfile generation). This can make workspace A (even running with `ignore-scripts=true`) posion global cache and execute scripts in workspace B. Users generally expect `ignore-scripts` to be sufficient to prevent immediate code execution on install (e.g. when the tree is just repacked/bundled without executing it). Here, that expectation is broken. Global state integrity is lost via operations that one would expect to be secure, enabling subsequently running arbitrary code execution on installs. Version 9.15.0 fixes the issue. As a work-around, use separate cache and store dirs in each workspace.
The package manager pnpm prior to version 9.15.0 seems to mishandle ov ...