CVE-2021-21320
User content sandbox can be confused into opening arbitrary documents
2.6
LOW
CVSS 3.1
EPSS 0.18%
Description
### Impact The user content sandbox can be abused to trick users into opening unexpected documents after several user interactions. The content can be opened with a `blob` origin from the Matrix client, so it is possible for a malicious document to access user messages and secrets. ### Patches This has been fixed by https://github.com/matrix-org/matrix-react-sdk/pull/5657, which is included in 3.15.0. ### Workarounds There are no known workarounds.
How to fix CVE-2021-21320
To remediate CVE-2021-21320, upgrade the affected package to a fixed version below.
- —upgrade to 3.15.0 or later
Is CVE-2021-21320 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 3.15.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW2.6 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N |