CVE-2021-29431CWE-20CWE-918

SSRF in Sydent due to missing validation of hostnames

High · published April 15, 2021

CVSS v3.1
7.7
EPSS
1%
Percentile
67.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.7 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.01194 · 67.8th percentile
Weaknesses
CWE-20 · Improper Input Validation; CWE-918 · Server-Side Request Forgery (SSRF)
Published
2021-04-15T21:00Z
EPSS history
Timeline
  • 15 APR 21:00Z
    SSRF in Sydent due to missing validation of hostnames
    cvelistv5