CVE-2021-21394 – Denial of service (via resource exhaustion) due to improper input validation on third-party identifier endpoints
https://notcve.org/view.php?id=CVE-2021-21394
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 1.28.0 Synapse is missing input validation of some parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion. Note that the groups feature is not part of the Matrix specification and the chosen maximum lengths are arbitrary. Not all clients might abide by them. • https://github.com/matrix-org/synapse/pull/9321 https://github.com/matrix-org/synapse/pull/9393 https://github.com/matrix-org/synapse/security/advisories/GHSA-w9fg-xffh-p362 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY https://pypi.org/project/matrix-synapse • CWE-20: Improper Input Validation •
CVE-2021-21333 – HTML injection in email and account expiry notifications
https://notcve.org/view.php?id=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. • https://github.com/matrix-org/synapse/commit/e54746bdf7d5c831eabe4dcea76a7626f1de73df https://github.com/matrix-org/synapse/pull/9200 https://github.com/matrix-org/synapse/releases/tag/v1.27.0 https://github.com/matrix-org/synapse/security/advisories/GHSA-c5f8-35qr-q4fm https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY • CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') •
CVE-2021-21332 – Cross-site scripting (XSS) vulnerability in the password reset endpoint
https://notcve.org/view.php?id=CVE-2021-21332
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 password reset endpoint served via Synapse was vulnerable to cross-site scripting (XSS) attacks. The impact depends on the configuration of the domain that Synapse is deployed on, but may allow access to cookies and other browser data, CSRF vulnerabilities, and access to other resources served on the same domain or parent domains. This is fixed in version 1.27.0. • https://github.com/matrix-org/synapse/commit/e54746bdf7d5c831eabe4dcea76a7626f1de73df https://github.com/matrix-org/synapse/pull/9200 https://github.com/matrix-org/synapse/releases/tag/v1.27.0 https://github.com/matrix-org/synapse/security/advisories/GHSA-246w-56m2-5899 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') •
CVE-2021-21273 – Open redirects on some federation and push requests
https://notcve.org/view.php?id=CVE-2021-21273
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. • https://github.com/matrix-org/synapse/commit/30fba6210834a4ecd91badf0c8f3eb278b72e746 https://github.com/matrix-org/synapse/pull/8821 https://github.com/matrix-org/synapse/releases/tag/v1.25.0 https://github.com/matrix-org/synapse/security/advisories/GHSA-v936-j8gp-9q3p https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY • CWE-601: URL Redirection to Untrusted Site ('Open Redirect') •
CVE-2021-21274 – Denial of service attack via .well-known lookups
https://notcve.org/view.php?id=CVE-2021-21274
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. • https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6 https://github.com/matrix-org/synapse/pull/8950 https://github.com/matrix-org/synapse/releases/tag/v1.25.0 https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY • CWE-400: Uncontrolled Resource Consumption CWE-770: Allocation of Resources Without Limits or Throttling •