CVE-2017-9785 Deserialization of Untrusted Data in NancyFX Nancy
Remote code execution is possible via deserialization of JSON data in a CSRF cookie within the NancyFX web framework.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-9785?
CVE-2017-9785 is a critical unsafe deserialization vulnerability in NancyFX Framework Up to 2.0.0, published on 20 Jul 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Csrf.cs in NancyFX Nancy before 1.4.4 and 2.x before 2.0-dangermouse has Remote Code Execution via Deserialization of JSON data in a CSRF Cookie.
Weakness: CWE-502
Which versions are affected by CVE-2017-9785?
4 open source packages ship an affected version, including Nancy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
Nancy NuGet | All versions | 1.4.4 |
Nancy NuGet | All versions | 1.4.4 |
Nancy NuGet | From 2.0.0-alpha | 2.0.0 |
Nancy NuGet | From 2.0.0-alpha | 2.0.0 |
Products include Nancyfx Nancy.
How do I fix CVE-2017-9785?
Upgrade Nancy to a fixed version for your release line: 1.4.4 or 2.0.0.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2017-9785 being exploited?
There is no known exploitation of CVE-2017-9785 in the wild and no public exploit code.
Sources
Also known as GHSA-mx3q-j2g2-5qxq.