CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
AI Score
Confidence
High
EPSS
Percentile
54.7%
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, a malicious homeserver could redirect requests to their .well-known file to a large file. This can lead to a denial of service attack where homeservers will consume significantly more resources when requesting the .well-known file of a malicious homeserver. This affects any server which accepts federation requests from untrusted servers. Issue is resolved in version 1.25.0. As a workaround the federation_domain_whitelist
setting can be used to restrict the homeservers communicated with over federation.
[
{
"product": "synapse",
"vendor": "matrix-org",
"versions": [
{
"status": "affected",
"version": ">=0.99.0, < 1.25.0"
}
]
}
]
github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6
github.com/matrix-org/synapse/pull/8950
github.com/matrix-org/synapse/releases/tag/v1.25.0
github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
AI Score
Confidence
High
EPSS
Percentile
54.7%