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GHSA-4fjv-pmhg-3rfg

MediumCVSS 6.8 / 10
Published Dec 4, 2020·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

Impact

  • Client implementations using this library

Issues

  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)

Patches

  1. IdToken signature is now always checked.
  2. JWA none algorithm is now allowed only if using the response_type code
  3. IdToken verification is now done automatically.
  4. iat claim is now checked for sanity.
Risk Scores
Base Score
6.8

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data.

Threat Intelligence
6.2

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.82%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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Medium severity
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