CVE-2021-32688
What it is
Nextcloud Server is a Nextcloud package that handles data storage. Nextcloud Server supports application specific tokens for authentication purposes. These tokens are supposed to be granted to a specific applications (e.g. DAV sync clients), and can also be configured by the user to not have any filesystem access. Due to a lacking permission check, the tokens were able to change their own permissions in versions prior to 19.0.13, 20.0.11, and 21.0.3. Thus fileystem limited tokens were able to grant themselves access to the filesystem. The issue is patched in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds aside from upgrading.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 2.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 2.3% in the next 30 days (EPSS).
- Severity: 8.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 2.3% · EPSS, next 30 days
- Weakness
- CWE-285
- Record status
- Modified
Affected
- Nextcloud Server < 19.0.13
- Nextcloud Server < 20.0.11
- Nextcloud Server < 21.0.3
- Fedoraproject Fedora 33
- Fedoraproject Fedora 34
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-32688.md and follow it. Check whether this project is affected by CVE-2021-32688. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-48m7-7r2r-838r
- https://github.com/nextcloud/server/pull/27000
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-48m7-7r2r-838r
- https://github.com/nextcloud/server/pull/27000
References
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-48m7-7r2r-838r
- https://github.com/nextcloud/server/pull/27000
- https://hackerone.com/reports/1193321
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BVZS26RDME2DYTKET5AECRIZDFUGR2AZ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J63NBVPR2AQCAWRNDOZSGRY5II4WS2CZ/
- https://security.gentoo.org/glsa/202208-17
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-48m7-7r2r-838r
- https://github.com/nextcloud/server/pull/27000
- https://hackerone.com/reports/1193321
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BVZS26RDME2DYTKET5AECRIZDFUGR2AZ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J63NBVPR2AQCAWRNDOZSGRY5II4WS2CZ/
- https://security.gentoo.org/glsa/202208-17