CVE-2021-37628 File Drop can be bypassed using Richdocuments app in nextcloud

What is CVE-2021-37628?

CVE-2021-37628 is a high-severity missing authorization vulnerability in nextcloud security-advisories, published on 7 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Nextcloud Richdocuments is an open source collaborative office suite. In affected versions the File Drop features ("Upload Only" public link shares in Nextcloud) can be bypassed using the Nextcloud Richdocuments app. An attacker was able to read arbitrary files in such a share. It is recommended that the Nextcloud Richdocuments is upgraded to 3.8.4 or 4.2.1. If upgrading is not possible then it is recommended to disable the Richdocuments application.

Weakness: CWE-639

Which versions are affected by CVE-2021-37628?

It affects 1 product.

Products include Nextcloud Richdocuments.

How do I fix CVE-2021-37628?

No fix has been published for CVE-2021-37628 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2021-37628 being exploited?

There is no known exploitation of CVE-2021-37628 in the wild and no public exploit code.

Other vulnerabilities in nextcloud security-advisories

• CVE-2022-31024 Federated editing allows iframing remote servers by default in richdocuments Medium 6.5
• CVE-2023-25150 Document content of files can be obtained through Collabora for files of other users Medium 5.8
• CVE-2023-28645 Secure view can be bypassed by using internal API endpoint in Nextcloud richdocuments Medium 5.7
• CVE-2021-37629 Lack of ratelimit on Richdocuments OCS endpoint in nextcloud Medium 5.3
• CVE-2021-39223 File path disclosure of shared files in Richdocuments application Medium 4.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-pxhh-954f-8w7w.