Bug 1482529 (CVE-2017-11424) - CVE-2017-11424 python-jwt: Incorrect handling of PEM-encoded public keys
Summary: CVE-2017-11424 python-jwt: Incorrect handling of PEM-encoded public keys
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2017-11424
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1482530 1482531 1483435 1526430
Blocks: 1482533
TreeView+ depends on / blocked
 
Reported: 2017-08-17 13:27 UTC by Adam Mariš
Modified: 2020-12-14 11:56 UTC (History)
7 users (show)

Fixed In Version: python-jwt 1.5.1
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Environment:
Last Closed: 2017-12-19 13:31:16 UTC
Embargoed:

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Description Adam Mariš 2017-08-17 13:27:42 UTC 
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.

Upstream bug:

https://github.com/jpadilla/pyjwt/pull/277
Comment 1 Adam Mariš 2017-08-17 13:27:59 UTC 
Created python-jwt tracking bugs for this issue:

Affects: epel-7 [bug 1482530]
Affects: fedora-all [bug 1482531]
Comment 3 Adam Mariš 2017-08-25 08:17:31 UTC 
CVE-2017-12880 was rejected in favour of CVE-2017-11424.
Comment 4 Siddharth Sharma 2017-10-09 03:49:38 UTC 
Analysis:

Python-jwt is shipped as dependency for heketi in Red Hat Gluster Storage 3. Heketi only uses token signatures (used algorithm HMAC HS256). Python-jwt is affected by this CVE but it does not affect Red Hat Gluster Storage 3 in the way it is being used.
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