Home/CVE/Sydent is a reference Matrix identity server. In Sydent versions 2.2.0 and prior, sissing input validation of some param
CVE

CVE-2021-29433

Sydent is a reference Matrix identity server. In Sydent versions 2.2.0 and prior, sissing input validation of some param

Sydent is a reference Matrix identity server. In Sydent versions 2.2.0 and prior, sissing 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. A patch for the vulnerability is in version 2.3.0.

No workarounds are known to exist.

MEDIUM · CVSS 4.3 EPSS 0.00281
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  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-20Improper Input Validation
CWE-400Uncontrolled Resource Consumption
▤

Affected Products & Versions

1
matrix sydent< 2.3.0
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
PyPI matrix-sydent MODERATE fixed in 2.3.0
▣

Scoring & Timeline

4.3
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD15 Apr 2021 · 06:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/matrix-org/sydent/commit/3175fd358ebc2c310eab7a3dbf296ce2bd54c1daPatchThird Party Advisory
https://github.com/matrix-org/sydent/security/advisories/GHSA-pw4v-gr34-2553PatchThird Party Advisory
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