CVE-2020-26891
Published: 19 October 2020
AuthRestServlet in Matrix Synapse before 1.21.0 is vulnerable to XSS due to unsafe interpolation of the session GET parameter. This allows a remote attacker to execute an XSS attack on the domain Synapse is hosted on, by supplying the victim user with a malicious URL to the /_matrix/client/r0/auth/*/fallback/web or /_matrix/client/unstable/auth/*/fallback/web Synapse endpoints.
Priority
Status
Package | Release | Status |
---|---|---|
matrix-synapse Launchpad, Ubuntu, Debian |
kinetic |
Ignored
(end of life, was needs-triage)
|
hirsute |
Ignored
(end of life)
|
|
bionic |
Needs triage
|
|
focal |
Needs triage
|
|
groovy |
Ignored
(end of life)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(1.21.1-1)
|
|
xenial |
Does not exist
|
|
jammy |
Needs triage
|
|
impish |
Ignored
(end of life)
|
|
lunar |
Not vulnerable
(1.64.0-3)
|
|
mantic |
Not vulnerable
(1.64.0-3)
|
Severity score breakdown
Parameter | Value |
---|---|
Base score | 6.1 |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | Required |
Scope | Changed |
Confidentiality | Low |
Integrity impact | Low |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |