CVE-2020-8289
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from...
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from improper certificate validation in bztransmit helper due to hardcoded whitelist of strings in URLs where validation is disabled leading to possible remote code execution via client update functionality.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from improper certificate validation in bztransmit helper due to hardcoded whitelist of strings in URLs where validation is disabled leading to possible remote code execution via client update functionality.
- Record
CVE-2020-8289- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 9.3 High
AV:N/AC:M/Au:N/C:C/I:C/A:C - Weakness
- CWE-295
- Updated
- 2026-11-02
CVE List No score
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from improper certificate validation in bztransmit helper due to hardcoded whitelist of strings in URLs where validation is disabled leading to possible remote code execution via client update functionality.
- Record
CVE-2020-8289- Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2020-29157 No score
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from improper certificate validation in bztransmit helper due to hardcoded whitelist of strings in URLs where validation is disabled leading to possible remote code execution via client update functionality.
- Record
EUVD-2020-29157- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-7f55-fqw6-8jjp No score
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from...
Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from improper certificate validation in bztransmit helper due to hardcoded whitelist of strings in URLs where validation is disabled leading to possible remote code execution via client update functionality.
- Record
GHSA-7f55-fqw6-8jjp- Weakness
- CWE-295
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | geffner/CVE-2020-8289 | 2020-09-09 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-8289 is a high vulnerability (CVSS 7.8) in Backblaze, published December 27, 2020. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 4.70%, the 91st percentile. No source names a fixed version.
References
hackerone.com/reports/818853
youtu.be/W0THXbcX5V8
github.com/geffner/CVE-2020-8289/blob/master/README.md
backblaze.com/blog/backblaze-cloud-backup-release-7-0-1
seclists.org/fulldisclosure/2020/Dec/57
nvd.nist.gov/vuln/detail/CVE-2020-8289