CVE-2021-21333

Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. 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.
Injection
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
6.1 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N
GitHub_MCNA
6.1 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N
CVEADP
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Base Score
CVSS 3.x
EPSS Score
Percentile: 66%
VendorProductVersion
matrixsynapse
𝑥
< 1.27.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
matrix-synapse
sid
1.116.0-3
fixed
trixie
1.116.0-3
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
matrix-synapse
noble
not-affected
mantic
not-affected
lunar
not-affected
kinetic
not-affected
jammy
not-affected
impish
not-affected
hirsute
not-affected
groovy
ignored
focal
needs-triage
bionic
needs-triage
xenial
dne
trusty
dne