Bug 1944138 (CVE-2021-21333) - CVE-2021-21333 matrix-synapse: HTML injection in email and account expiry notifications
Summary: CVE-2021-21333 matrix-synapse: HTML injection in email and account expiry not...
Alias: CVE-2021-21333
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1944139
TreeView+ depends on / blocked
Reported: 2021-03-29 11:40 UTC by Michael Kaplan
Modified: 2021-03-29 17:35 UTC (History)
2 users (show)

Fixed In Version: matrix-synapse 1.27.0
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Last Closed: 2021-03-29 17:35:12 UTC

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Description Michael Kaplan 2021-03-29 11:40:58 UTC
In Synapse before version 1.27.0, the notification emails sent for notifications for missed messages or for an expiring account are subject to HTML injection. In the case of the notification for missed messages, this could allow an attacker to insert forged content into the email. The account expiry feature is not enabled by default and the HTML injection is not controllable by an attacker. This is fixed in version 1.27.0.

Comment 2 Michael Kaplan 2021-03-29 11:41:24 UTC
Created matrix-synapse tracking bugs for this issue:

Affects: fedora-all [bug 1944139]

Comment 3 Product Security DevOps Team 2021-03-29 17:35:12 UTC
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.

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