Incorrect string comparison in `iss` checking allows for denial of service scenarios

CVE-2024-53861
2.2LOW

Key Information

Vendor
Jpadilla
Status
Pyjwt
Vendor
CVE Published:
29 November 2024

Summary

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.

Affected Version(s)

pyjwt = = 2.10.0

CVSS V3.1

Score:
2.2
Severity:
LOW
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
High
User Interaction:
None
Scope:
Unchanged

Timeline

  • Risk change from: 0 to: 2.2 - (LOW)

  • Vulnerability published.

  • Vulnerability Reserved.

Collectors

NVD DatabaseMitre Database
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