CVE-2017-11424

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.

CVSS v3 7.5 HIGH
CVSS v2.0 5.0 MEDIUM

7.5^/10

CVSS v3 : HIGH

Vector : AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

5.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:N/C:N/I:P/A:N

Exploitability : 10.0 / Impact : 2.9

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
http://www.debian.org/security/2017/dsa-3979	Third Party Advisory
https://github.com/jpadilla/pyjwt/pull/277	Issue Tracking Patch Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*

Configuration 2 (hide)

OR	cpe:2.3:o:debian:debian_linux:8.0:::::::*
	cpe:2.3:o:debian:debian_linux:9.0:::::::*

History

No history.

Information

Published : 2017-08-24 16:29

Updated : 2019-10-03 00:03

NVD link : CVE-2017-11424

Mitre link : CVE-2017-11424

CVE.ORG link : CVE-2017-11424

JSON object : View

Products Affected

debian

debian_linux

pyjwt_project

pyjwt

CWE

NVD-CWE-noinfo

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