CVE-2023-28999

MEDIUM6.9

Nextcloud: Lack of authenticity of metadata keys allows a malicious server to gain access to E2EE folders

Published Apr 4, 2023

Modified 11 months ago

No fix available

Details

Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files. This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.

References

WEBhttps://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_DanieleCoppola.pdf WEBhttps://github.com/nextcloud/desktop/pull/5560 WEBhttps://github.com/nextcloud/security-advisories/security/advisories/GHSA-8875-wxww-3rr8 ADVISORYhttps://www.cve.org/CVERecord?id=CVE-2023-28999

CVSS Analysis

CVSS v3.1

6.9

Exploitability

Attack Vector

PhysicalAV:P

Attack Complexity

LowAC:L

Privileges Required

HighPR:H

User Interaction

RequiredUI:R

Scope

ChangedS:C

Impact

Confidentiality

HighC:H

Integrity

HighI:H

Availability

LowA:L

6.9/CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L

Weakness Type (CWE)

Other

CWE-325

Ecosystems

Timeline

PublishedApr 4, 2023

ModifiedFeb 11, 2025