CVE-2023-35173 — Nextcloud End-to-end encryption app provides all the necessary APIs to implement

Nextcloud End-to-end encryption app provides all the necessary APIs to implement End-to-End encryption on the client side. By providing an invalid meta data file, an attacker can make previously dropped files inaccessible. It is recommended that the Nextcloud End-to-end encryptio

01What is this vulnerability?

Nextcloud End-to-end encryption app provides all the necessary APIs to implement End-to-End encryption on the client side. By providing an invalid meta data file, an attacker can make previously dropped files inaccessible. It is recommended that the Nextcloud End-to-end encryption app is upgraded to version 1.12.4 that contains the fix.

02Affected products

Vendor	Product	Versions
nextcloud	security	advisories — >= 1.12.0, < 1.12.4

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-06-23T20:50:15.948Z
• Last modified: 2024-08-02T16:23:59.642Z

09References

• github.com — https://github.com/nextcloud/security-advisories/security/advisories/GHSA-x7c7-v…
• github.com — https://github.com/nextcloud/end_to_end_encryption/pull/435
• hackerone.com — https://hackerone.com/reports/1914115