Description:
daneren2005 DSub for Subsonic (Android client) version 5.4.1 contains a
CWE-295: Improper Certificate Validation vulnerability in HTTPS Client that
can result in any non-CA signed server certificate, including self signed
and expired, being accepted by the client. This attack appear to be
exploitable when the victim connects to a server that's MITM/Proxied by an
attacker.

Affected Product: DSub for Subsonic (Android client)
Vendor of Product: daneren2005
Version Affected: 5.4.2 (latest as of Sept 4, 2018) and below

CVE: CVE-2018-1000664
Status: Still unpatched as of time of writing
Vulnerability Type: CWE-295: Improper Certificate Validation
Attack Type: Remote
Attack Vectors: To exploit the vulnerability, a MITM attacker can provide
any untrusted or expired certificate to the client.

Discoverer: Andrew Klaus (andrewklaus@gmail.com)

Mitigation: The only mitigation is to not run over an untrusted network or
use an app that does verify the certificate as valid. Another client called
Ultrasonic, available on the Play Store and is Free and Open Source,
successfully verified the server TLS certificate.

Other notes: There has been an open ticket on GitHub since Nov 2012 that
confirms self-signed certificates are allowed by the application:
https://github.com/daneren2005/Subsonic/issues/60

Timeline:
Aug 20, 2018: Contacted developer via Twitter and GitHub with no reply
Sept 4, 2018: Assigned CVE
Sept 4, 2018: Disclosing to Full Disclosure