CVE-2021-212733.1LowCWE-601

CVE-2021-21273: Open redirects on some federation and push requests

matrix-org · synapse

Fixed in 1.25.0 · Affected: matrix-org synapse before 1.25.0 · Exploitation: possible (1 to 10%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

1.8%probability of exploitation in the next 30 days

78th percentile

050100

Higher than 78% of scored CVEs

3.1LowCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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 1.25.0, requests to user provided domains were not restricted to external IP addresses when calculating the key validity for third-party invite events and sending push notifications. This could cause Synapse to make requests to internal infrastructure. The type of request was not controlled by the user, although limited modification of request bodies was possible. For the most thorough protection server administrators should remove the deprecated `federation_ip_range_blacklist` from their settings after upgrading to Synapse v1.25.0 which will result in Synapse using the improved default IP address restrictions. See the new `ip_range_blacklist` and `ip_range_whitelist` settings if more specific control is necessary.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

matrix-org · synapse< 1.25.0

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Possible (1 to 10%). EPSS between 1% and 10%.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Open Redirect
Vendor: matrix-org
Published: February 2021
Band: Possible (1 to 10%), February 2021

CoverageNo articles yet

No CyberSIXT article names CVE-2021-21273 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.