Bug 1999744 (CVE-2021-39134)

Summary: CVE-2021-39134 nodejs-arborist: symlink following vulnerability
Product: [Other] Security Response Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: hhorak, jorton, kaycoth, mrunge, nodejs-maint, nodejs-sig, psegedy, sgallagh, thrcka, zsvetlik
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: nodejs-npmcli-arborist 2.8.2, npm 7.21.0 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in nodejs-arborist. On case-insensitive file systems (such as macOS and Windows), Arborist’s internal data structure did not see multiple dependencies as separate items that could coexist within the same level in the node_modules hierarchy when they differ only in the case of their name. This issue, combined with a symlink dependency such as file:/some/path, allows an attacker to create a situation in which arbitrary contents are written to any location on the filesystem. The highest threat from this vulnerability is to integrity and system availability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 2029556    
Bug Blocks: 1999749    

Description Guilherme de Almeida Suckevicz 2021-08-31 16:53:50 UTC
@npmcli/arborist, the library that calculates dependency trees and manages the node_modules folder hierarchy for the npm command line interface, aims to guarantee that package dependency contracts will be met, and the extraction of package contents will always be performed into the expected folder.

This is, in part, accomplished by resolving dependency specifiers defined in package.json manifests for dependencies with a specific name, and nesting folders to resolve conflicting dependencies.

When multiple dependencies differ only in the case of their name, Arborist's internal data structure saw them as separate items that could coexist within the same level in the node_modules hierarchy. However, on case-insensitive file systems (such as macOS and Windows), this is not the case. Combined with a symlink dependency such as file:/some/path, this allowed an attacker to create a situation in which arbitrary contents could be written to any location on the filesystem.

For example, a package pwn-a could define a dependency in their package.json file such as "foo": "file:/some/path". Another package, pwn-b could define a dependency such as FOO: "file:foo.tgz". On case-insensitive file systems, if pwn-a was installed, and then pwn-b was installed afterwards, the contents of foo.tgz would be written to /some/path, and any existing contents of /some/path would be removed.

Anyone using npm v7.20.6 or earlier on a case-insensitive filesystem is potentially affected.

Reference:
https://github.com/npm/arborist/security/advisories/GHSA-2h3h-q99f-3fhc

Comment 3 Cedric Buissart 2021-12-06 16:51:42 UTC
* npm versions v7 until older than v7.21.0 are affected
* npm versions v7.21.0 and newer (including v8.0.0) are not affected
* npm versions 6.x and older are not using @npmcli/arborist, and thus are not affected

Comment 4 Cedric Buissart 2021-12-06 18:45:42 UTC
Created nodejs:16/nodejs tracking bugs for this issue:

Affects: fedora-all [bug 2029556]