Rapid7 Vulnerability & Exploit Database

Ubuntu: USN-3407-1 (CVE-2017-11424): PyJWT vulnerability

Free InsightVM Trial No Credit Card Necessary
Watch Demo See how it all works
Back to Search

Ubuntu: USN-3407-1 (CVE-2017-11424): PyJWT vulnerability

Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:P/A:N)
Published
08/24/2017
Created
07/25/2018
Added
08/31/2017
Modified
03/02/2020

Description

In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.

Solution(s)

  • ubuntu-upgrade-python-jwt
  • ubuntu-upgrade-python3-jwt

References

  • USN-3407-1
  • DSA-3979
  • CVE-2017-11424

insightVM

Advanced vulnerability management analytics and reporting.
Key Features
Free InsightVM Trial View All Features

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;