VU#293714: Arbitrary File Overwrite in Develar app-builder (zipx.Unzip) via Symlink Following on macOS (APFS)

Summary

Overview A vulnerability in the zipx.Unzip extraction routine of Develar’s app-builder allows an attacker to overwrite arbitrary files on macOS using Apple File System (APFS). The issue arises from a combination of Unicode normalization collisions and unsafe symlink-following behavior. APFS treats certain Unicode equivalent filenames as identical (e.g., ß ↔ ss), while app builder performs no canonical normalization before validating or writing paths. Description Develar’s app-builder is a command‑line build tool used heavily in the Electron ecosystem to package, sign, notarize, and produce distributable application bundles for macOS, Windows, and Linux. It is popular because it is a transitive dependency of electron-builder, one of the most widely used packaging tools for Electron apps. The vulnerability arises from how the zipx.Unzip...

Why it matters

CERT/CC notes often cover coordinated disclosures, multi-vendor exposure, infrastructure risk, or cases where remediation guidance is still developing.

Operator check

Review the CERT/CC Vulnerability Note and compare the affected vendor and product list against your inventory. Apply vendor fixes or compensating controls for app-builder (zipx.Unzip) via Symlink Following on macOS (APFS) where available.

Sources