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Fencer Vulns
high 7.8

CVE-2020-8290 json

Backblaze for Windows and Backblaze for macOS before 7.0.0.439 suffer from improper privilege management in `bztransmit` helper due to lack…

published 2020-12-27 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-29158

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

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.

Patch / fix

  • backblaze backblaze 7.0.0.439

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • youtu.be https://youtu.be/OpC6neWd2aM referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/geffner/CVE-2020-8290/blob/master/README.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • n/a Backblaze

Classification

Weakness
  • CWE-269 Improper Privilege Management

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.