CVE-2023-28998

Public Exploit
Nextcloud Desktop client misbehaves with E2EE when the server returns empty list of metadata keys

Description

The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server. Starting with version 3.0.0 and prior to version 3.6.5, 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.​ Users should upgrade the Nextcloud Desktop client to 3.6.5 to receive a patch. No known workarounds are available.

Category

6.7
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.64%
Vendor Advisory github.com Vendor Advisory github.com
Affected: nextcloud security-advisories
Published at:
Updated at:

References

Link Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-jh3g-wpwv-cqgr vendor advisory
https://github.com/nextcloud/desktop/pull/5323 patch vendor advisory
https://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_DanieleCoppola.pdf third party advisory exploit technical description

Frequently Asked Questions

What is the severity of CVE-2023-28998?
CVE-2023-28998 has been scored as a medium severity vulnerability.
How to fix CVE-2023-28998?
To fix CVE-2023-28998, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-28998 being actively exploited in the wild?
It is possible that CVE-2023-28998 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-28998?
CVE-2023-28998 affects nextcloud security-advisories.
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