CVE-2023-28999

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

Severity Score

6.4

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

Low

Attack Vector

Physical

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

Low

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2023-03-29 CVE Reserved
2023-04-04 CVE Published
2024-08-02 CVE Updated
2024-08-02 First Exploit
2024-09-14 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-311: Missing Encryption of Sensitive Data
CWE-325: Missing Cryptographic Step

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC
https://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_DanieleCoppola.pdf	2024-08-02

URL	Date	SRC
https://github.com/nextcloud/desktop/pull/5560	2023-11-07

URL	Date	SRC
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8875-wxww-3rr8	2023-11-07

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nextcloud Search vendor "Nextcloud"		Desktop Search vendor "Nextcloud" for product "Desktop"				>= 3.0.0 < 3.8.0 Search vendor "Nextcloud" for product "Desktop" and version " >= 3.0.0 < 3.8.0"		-		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Search vendor "Nextcloud" for product "Nextcloud"				>= 3.0.5 < 4.8.0 Search vendor "Nextcloud" for product "Nextcloud" and version " >= 3.0.5 < 4.8.0"		iphone_os		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Search vendor "Nextcloud" for product "Nextcloud"				>= 3.13.0 < 3.25.0 Search vendor "Nextcloud" for product "Nextcloud" and version " >= 3.13.0 < 3.25.0"		android		Affected