CVE-2020-26257 log

Source	CVE Red Hat MITRE NVD Debian Ubuntu SUSE Alpine Mageia CVE Details CIRCL Bugs Arch Linux Red Hat Gentoo SUSE GitHub Lists oss-security full-disclosure bugtraq Misc GitHub code web search
Severity	Medium
Remote	Yes
Type	Denial of service
Description	A security issue was found in matrix-synapse before version 1.23.1. A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a /send_join, /send_leave, /invite or /exchange_third_party_invite request. This can lead to a denial of service in which future events will not be correctly sent to other servers over federation. This affects any server which accepts federation requests from untrusted servers.

Group	Package	Affected	Fixed	Severity	Status	Ticket
AVG-1341	matrix-synapse	1.23.0-1	1.24.0-1	Medium	Fixed

References
https://github.com/matrix-org/synapse/security/advisories/GHSA-hxmp-pqch-c8mm https://github.com/matrix-org/synapse/pull/8776 https://github.com/matrix-org/synapse/commit/3ce2f303f15f6ac3dc352298972dc6e04d9b7a8b

References

https://github.com/matrix-org/synapse/security/advisories/GHSA-hxmp-pqch-c8mm
https://github.com/matrix-org/synapse/pull/8776
https://github.com/matrix-org/synapse/commit/3ce2f303f15f6ac3dc352298972dc6e04d9b7a8b

Notes
Workaround ========== This issue can be mitigated by limiting access to the federation API to trusted servers (for example by using federation_domain_whitelist).