CVE-2021-32679 Filenames not escaped by default in controllers using DownloadResponse
Attackers can trick users into downloading malicious executables disguised as benign files due to unescaped filenames in download responses.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-32679?
CVE-2021-32679 is a low-severity vulnerability in Fedoraproject Fedora, published on 12 Jul 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.0.11, and 21.0.3, filenames where not escaped by default in controllers using `DownloadResponse`. When a user-supplied filename was passed unsanitized into a `DownloadResponse`, this could be used to trick users into downloading malicious files with a benign file extension. This would show in UI behaviours where Nextcloud applications would display a benign file extension (e.g. JPEG), but the file will actually be downloaded with an executable file extension. The vulnerability is patched in versions 19.0.13, 20.0.11, and 21.0.3. Administrators of Nextcloud instances do not have a workaround available, but developers of Nextcloud apps may manually escape the file name before passing it into `DownloadResponse`.
Weakness: CWE-116
Which versions are affected by CVE-2021-32679?
It affects 2 products.
Products include Fedoraproject Fedora, Nextcloud Nextcloud Server.
How do I fix CVE-2021-32679?
Upgrade to a fixed version.
Is CVE-2021-32679 being exploited?
There is no known exploitation of CVE-2021-32679 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as GHSA-3hjp-26x8-mhf6.