NancyFX Nancy up to 1.4.3/2.0 JSON Data Csrf.cs CSRF deserialization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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A vulnerability was found in NancyFX Nancy up to 1.4.3/2.0 and classified as critical. Affected by this issue is an unknown part of the file Csrf.cs of the component JSON Data Handler. The manipulation with an unknown input leads to a deserialization vulnerability (CSRF). Using CWE to declare the problem leads to CWE-502. The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The bug was discovered 07/20/2017. The weakness was shared 07/20/2017 (GitHub Repository). The advisory is shared for download at This vulnerability is handled as CVE-2017-9785 since 06/21/2017. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

Upgrading to version 1.4.4 or 2.0-dangermouse eliminates this vulnerability.




CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.7

VulDB Base Score: 6.3
VulDB Temp Score: 5.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍



VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍


Name: CSRF
Class: Deserialization / CSRF
CWE: CWE-502 / CWE-20
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Nancy 1.4.4/2.0-dangermouse


06/21/2017 🔍
07/20/2017 +29 days 🔍
07/20/2017 +0 days 🔍
07/20/2017 +0 days 🔍
07/20/2017 +0 days 🔍
12/13/2022 +1972 days 🔍


Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-9785 (🔍)


Created: 07/20/2017 08:09 PM
Updated: 12/13/2022 01:03 PM
Changes: 07/20/2017 08:09 PM (60), 10/30/2019 08:17 PM (2), 12/13/2022 01:03 PM (4)
Complete: 🔍


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