CVE-2021-29433— Denial of service (via resource exhaustion) due to improper input validation
Get alerts for future matching vulnerabilitiesLog in to subscribe
I. Basic Information for CVE-2021-29433
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗ Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Denial of service (via resource exhaustion) due to improper input validation
Source: NVD (National Vulnerability Database)
Vulnerability Description
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.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Source: NVD (National Vulnerability Database)
Vulnerability Type
输入验证不恰当
Source: NVD (National Vulnerability Database)
Vulnerability Title
Matrix Sydent 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Matrix Sydent是英国Matrix基金会的一款Matrix身份验证服务器API的实现。 Matrix Sydent 存在输入验证错误漏洞，该漏洞源于缺少对某些参数的输入验证可能会导致磁盘空间和内存的过度使用，从而导致资源耗尽。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| matrix-org | sydent | <= 2.2.0 | - |
II. Public POCs for CVE-2021-29433
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POCPremium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2021-29433
请登录查看更多情报信息。
- https://github.com/matrix-org/sydent/security/advisories/GHSA-pw4v-gr34-2553x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2021-29433
Same Patch Batch · matrix-org · 2021-04-15 · 4 CVEs total
| CVE-2021-29431 | 7.7 HIGH | SSRF in Sydent due to missing validation of hostnames |
| CVE-2021-29430 | 7.5 HIGH | Denial of service attack via memory exhaustion |
| CVE-2021-29432 | 5.3 MEDIUM | Malicious users could control the content of invitation emails |
IV. Related Vulnerabilities
Same vendor: matrix-org
- CVE-2025-66622
matrix-sdk-base is vulnerable to DoS via custom m.room.join_ - CVE-2025-59160
matrix-js-sdk has insufficient validation when considering a - CVE-2025-59047
matrix-sdk-base has panic in the `RoomMember::normalized_pow - CVE-2025-53549
Matrix Rust SDK allows SQL injection in the EventCache imple - CVE-2025-48937
matrix-sdk-crypto vulnerable to sender of encrypted events b
Same weakness: CWE-20
V. Comments for CVE-2021-29433
No comments yet