CVE-2021-32679Filenames not escaped by default in controllers using DownloadResponse
- 3.5LowCVSS base score
- 1.4%Exploitation in 30 daysEPSS · top 28% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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`.
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Low3.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N |
| NVDNVD · Modified | 3.1 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.4% · top 28% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.5.
Affected products
nextcloud · security-advisories
- affected < 19.0.13
- affected >= 20.0.0, < 20.0.11
- affected >= 21.0.0, < 21.0.3
References
References6
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3hjp-26x8-mhf6 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/nextcloud/server/pull/27354 (opens in a new tab)x_refsource_MISCx_transferred
- https://hackerone.com/reports/1215263 (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2021-9b421b78af (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2021-6f327296fe (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- GLSA-202208-17 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-19487 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-32679)Record last updated .