Medium

Insecure temporary file in Netflix OSS Hollow

  • Disclosed: 29.03.2021
  • Updated: 11.10.2026 11:21

ID: NFLX-2021-001 Title: Local information disclosure in Hollow Release Date: 2021-03-23 Credit: Security Researcher @JLLeitschuh

Overview

Security researcher @JLLeitschuh reported that Netflix Hollow (a Netflix OSS project available here: https://github.com/Netflix/hollow) writes to a local temporary directory before validating the permissions on it.

Impact

An attacker with the ability to create directories and set permissions on the local filesystem could pre-create this directory and read or modify anything written there by the Hollow process.

Description

Since the Files.exists(parent) is run before creating the directories, an attacker can pre-create these directories with wide permissions. Additionally, since an insecure source of randomness is used, the file names to be created can be deterministically calculated.

Workarounds and Fixes

Avoid running Hollow in configurations that share a filesystem with less-trusted processes. May be fixed in a future release.

Affected software

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PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) com.netflix.hollow:hollow <= 6.1.0 no fix

References

CVSS score 4.4/10
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness (CWE)
CWE-377
Platform
Java / Kotlin (Maven)
Package
com.netflix.hollow:hollow
Disclosed
29.03.2021
Updated
11.10.2026 11:21

Sources and licenses

OSV / GitHub Advisory Database - GHSA-9295-mhf3-v33m - CC BY 4.0

Vulnerability history: com.netflix.hollow:hollow

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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