Matrix
CVE-2021-29430
HIGH
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
1DescriptionNVD
Sydent is a reference Matrix identity server. Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to memory exhaustion and denial of service. Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service. This affects any server which accepts registration requests from untrusted clients. This issue has been patched by releases 89071a1, 0523511, f56eee3. As a workaround request sizes can be limited in an HTTP reverse-proxy. There are no known workarounds for the problem with overlarge responses.
AnalysisAI
Sydent is a reference Matrix identity server. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Technical ContextAI
This vulnerability is classified under CWE-20. Sydent is a reference Matrix identity server. Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to memory exhaustion and denial of service. Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service. This affects any server which accepts registration requests from untrusted clients. This issue has been patched by releases 89071a1, 0523511, f56eee3. As a workaround request sizes can be limited in an HTTP reverse-proxy. There are no known workarounds for the problem with overlarge responses. Affected products include: Matrix Sydent.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an
An issue was discovered in core/assets/form/form_question_types/form_question_type_file_upload/form_question_type_file_u
An issue was discovered in Squiz Matrix CMS 5.5.0 prior to 5.5.0.3, 5.5.1 prior to 5.5.1.8, 5.5.2 prior to 5.5.2.4, and
matrix-appservice-irc is a Node.js IRC bridge for Matrix. Rated critical severity (CVSS 9.8), this vulnerability is remo
The olm_session_describe function in Matrix libolm before 3.2.7 is vulnerable to a buffer overflow. Rated critical sever
Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Rated critical severity (CVSS 9.8), t
An issue was discovered in Matrix libolm through 3.2.16. Rated medium severity (CVSS 5.3), this vulnerability is remotel
An issue was discovered in Matrix libolm through 3.2.16. Rated medium severity (CVSS 5.3), this vulnerability is remotel
An issue was discovered in Squiz Matrix before 5.3.6.1 and 5.4.x before 5.4.1.3. Rated high severity (CVSS 8.8), this vu
matrix-hookshot is a Matrix bot for connecting to external services like GitHub, GitLab, JIRA, and more. Rated critical
matrix-appservice-irc is an open source Node.js IRC bridge for Matrix. Rated high severity (CVSS 8.8), this vulnerabilit
gomatrixserverlib is a Go library for matrix protocol federation. Rated high severity (CVSS 8.8), this vulnerability is
Same weakness CWE-20 – Improper Input Validation
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today