CVE-2020-8290

HIGH

Backblaze <7.0.0.439 - Privilege Escalation

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2020-8290. PoCs published by geffner.

AI-analyzed exploit summary This repository contains a functional proof-of-concept exploit for CVE-2020-8290, demonstrating a local privilege escalation vulnerability in Backblaze for Windows and macOS. The exploit leverages insecure directory permissions to replace a downloaded update executable, allowing an unprivileged user to gain SYSTEM/root privileges.

Description

Backblaze for Windows and Backblaze for macOS before 7.0.0.439 suffer from improper privilege management in `bztransmit` helper due to lack of permission handling and validation before creation of client update directories allowing for local escalation of privilege via rogue client update binary.

Exploits (1)

nomisec WORKING POC
by geffner · poc
https://github.com/geffner/CVE-2020-8290

This repository contains a functional proof-of-concept exploit for CVE-2020-8290, demonstrating a local privilege escalation vulnerability in Backblaze for Windows and macOS. The exploit leverages insecure directory permissions to replace a downloaded update executable, allowing an unprivileged user to gain SYSTEM/root privileges.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: Backblaze for Windows and macOS (versions before 7.0.0.439)
Auth required
Prerequisites: Local access to the target system · Backblaze installed and running · Unprivileged user account
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (3)

Core 3
Core References
Permissions Required x_refsource_misc
https://hackerone.com/reports/818857
Exploit, Third Party Advisory x_refsource_misc
https://youtu.be/OpC6neWd2aM

Scores

CVSS v3 7.8
EPSS 0.0058
EPSS Percentile 43.2%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-269
Status published
Products (1)
backblaze/backblaze < 7.0.0.439 (2 CPE variants)
Published Dec 27, 2020
Tracked Since Feb 18, 2026