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CVE-2021-29431

SSRF in Sydent due to missing validation of hostnames

Published: Apr 15, 2021Updated: Nov 21, 2024 Sources: CVE List NVD GHSACWE-20
7.7HIGH
NVD MITRE
EPSS Score
1.2%
Top 34.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

Sydent is a reference Matrix identity server. Sydent can be induced to send HTTP GET requests to internal systems, due to lack of parameter validation or IP address blacklisting. It is not possible to exfiltrate data or control request headers, but it might be possible to use the attack to perform an internal port enumeration. This issue has been addressed in in 9e57334, 8936925, 3d531ed, 0f00412. A potential workaround would be to use a firewall to ensure that Sydent cannot reach internal HTTP resources.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:CC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-20CWE-918

Affected Products

matrix
oss-project·GBaka javascript sdk, synapse, matrix irc bridge
sydentOn-prem
Communications / messaging-chat
PyPI
package-ecosystem
matrix-sydent
OSS Libraries
matrix-org
oss-project·DEaka synapse, matrix appservice irc, matrix-js-sdk
sydent
Communications / messaging-chat

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Command and Control
Initial Access
View detailed technique mapping

References

https://github.com/matrix-org/sydent/commit/0f00412017f25619bc36c264b29ea96808bf310a
github.com
https://github.com/matrix-org/sydent/commit/3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3
github.com
https://github.com/matrix-org/sydent/commit/8936925f561b0c352c2fa922d5097d7245aad00a
github.com
and 8 more references View all →

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