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Feb 16, 2018

Psiphon Completes Another Third Party Security Review

In late June 2017, Psiphon continued to prove its commitment to open source development (you can access our code repository here), by commissioning Cure53 to perform a security audit of our services. The security review took 22 days and a total of 9 testers to complete what was described as a review with a “vast scope” and the Cure53 testers were very thorough. This is our 2nd security audit of this kind in 3 years (you can see the results of the 1st one, performed by iSec here).
The report’s description of what was included in the scope reads:
“In scope were multiple components of the Psiphon software compound, including the tunnel-core client and server, the library glue, the Psiphon iOS app and, last but not least, the Psiphon iOS browser. This very broad premise and scope explain the necessity for involving a rather large number of testers with properly matched expertise in different arenas. In sum, the tests included code audits, actual penetration tests, protocol and configuration reviews, and a cryptographic audit."
We are very happy with the results of the security audit and proud to relay that “no noteworthy security risks could be unveiled” (pg.19). In the spirit of transparency you can read the full detailed report in pdf form here. Of the two vulnerabilities found, one has already been fixed (and confirmed by Cure53) and steps have been taken to address the other in upcoming releases.
The testers also noted 7 other miscellaneous issues that you can find listed in the report, four of these have also already been addressed.
The testers shared a conviction that the software compound greatly benefitted from a number of software security audits in the past. Needless to say, this is reflected in findings. Among the total nine issues discovered, only two were marked as security vulnerabilities and were further ascribed with the lowest “Informational” severity ranking.”
The Cure53 testers noted several times throughout the report how clean and quality driven the code is and came to the following conclusion:
“Despite investing considerable time and personnel resources into attempting a compromise, the Psiphon components in scope held up to scrutiny and presented themselves strong and robust in face of adversarial efforts. The bottom line is that no noteworthy security risks could be unveiled.”

We hope that you will find this report interesting, and that it will assure you of our commitment to providing first-class software that will always be open source and secure.