CVE-2020-26244 - CVE House
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Status published Medium CVE-2020-26244

Cryptographic issues in Python oic

Vulnerability Description

Python oic is a Python OpenID Connect implementation. In Python oic before version 1.2.1, there are several related cryptographic issues affecting client implementations that use the library. The issues are: 1) The IdToken signature algorithm was not checked automatically, but only if the expected algorithm was passed in as a kwarg. 2) JWA `none` algorithm was allowed in all flows. 3) oic.consumer.Consumer.parse_authz returns an unverified IdToken. The verification of the token was left to the discretion of the implementator. 4) iat claim was not checked for sanity (i.e. it could be in the future). These issues are patched in version 1.2.1.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

pyoidc
Vulnerable Versions:
< 1.2.1

Timeline

Official Publish: December 2nd, 2020
Last Modified: August 4th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Weaknesses (CWE)

CWE-325 CWE-347

MITRE ATT&CK TTPs

T1553 Subvert Trust Controls
Defense Evasion
T1190 Exploit Public-Facing Application
Initial Access
T1078 Valid Accounts
Persistence
T1550 Use Alternate Authentication Material
Defense Evasion
T1565 Data Manipulation
Impact