Description

@xhmikosr/decompress: Path traversal via symlink chain

Impact

When extracting an untrusted archive with the default decompress(input, output) API, a crafted archive containing a chain of symlink entries can make a later entry resolve outside the output directory. The lexical containment checks pass, but the kernel follows the planted symlinks to a path outside output, letting an attacker write (and read) files outside the intended extraction directory. Overwriting startup scripts or configuration can lead to remote code execution.

This is a bypass of the hardening in GHSA-mp2f-45pm-3cg9. Any application that extracts attacker-controlled archives is affected.

Patches

Fixed in 11.1.4 (latest) and backported to 10.2.2 (release-v10 dist-tag). Upgrade to one of these.

The unmaintained upstream decompress package shares this flaw and will not be patched. Migrate to @xhmikosr/decompress@11.1.4 (or @10.2.2).

Workarounds

None. Do not extract untrusted archives on affected versions. If you cannot upgrade, validate entries out of band and reject any whose resolved path escapes the target directory.

Mitigation

Aliases

References