CVE-2024-53861

Publication date 29 November 2024

Last updated 30 May 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

2.2 · Low

Score breakdown

pyjwt is a JSON Web Token implementation in Python. An incorrect string comparison is run for `iss` checking, resulting in `“acb”` being accepted for `“_abc_”`. This is a bug introduced in version 2.10.0: checking the “iss” claim changed from `isinstance(issuer, list)` to `isinstance(issuer, Sequence)`. Since str is a Sequnce, but not a list, `in` is also used for string comparison. This results in `if “abc” not in “__abcd__”:` being checked instead of `if “abc” != “__abc__”:`. Signature checks are still present so real world impact is likely limited to denial of service scenarios. This issue has been patched in version 2.10.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Read the notes from the security team

Status

Package Ubuntu Release Status
pyjwt 24.10 oracular
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected

Notes

hlibk

The issue was introduced in 2.10.0. No Ubuntu release currently contains the vulnerable code.

Severity score breakdown

Parameter Value
Base score 2.2 · Low
Attack vector Network
Attack complexity High
Privileges required High
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N