CVEs-PoC/2018/CVE-2018-10903.md

### [CVE-2018-10903](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-10903)
![](https://img.shields.io/static/v1?label=Product&message=python-cryptography&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-20&color=brighgreen)

### Description

A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.

### POC

#### Reference
- https://usn.ubuntu.com/3720-1/

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/AdiRashkes/python-tda-bug-hunt-2
- https://github.com/sonatype-nexus-community/jake