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Initialization vector reuse in end-to-end encryption allows a malicious server admin to break manipulate and access files

Moderate
nickvergessen published GHSA-4p33-rw27-j5fc Apr 4, 2023

Package

Desktop (Nextcloud)

Affected versions

>= 3.0.0

Patched versions

3.6.5

Description

Impact

A malicious server administrator can recover and modify the contents of E2EE files.

Patches

It is recommended that the Nextcloud Desktop client is upgraded to 3.6.5

Workarounds

  • No workaround available

References

Credit

  • Martin Albrecht (Royal Holloway, University of London/Kings College London)
  • Matilda Backendal (ETH Zurich)
  • Daniele Coppola (ETH Zurich)
  • Kenneth G. Paterson (ETH Zurich)

For more information

If you have any questions or comments about this advisory:

Severity

Moderate
6.7
/ 10

CVSS base metrics

Attack vector
Physical
Attack complexity
Low
Privileges required
High
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None
CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

CVE ID

CVE-2023-28997

Weaknesses