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CVE-2021-22160

Authentication with JWT allows use of “none”-algorithm

CRITICAL
9.8
CVSS Score
Published: May 26, 2021 at 12:22 PM UTC
Updated: June 17, 2026 at 03:36 AM UTC
1 product affected across 1 vendorPulsar

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Severity
CRITICAL9.8
Exploit prediction
EPSS 53%

Description

If Apache Pulsar is configured to authenticate clients using tokens based on JSON Web Tokens (JWT), the signature of the token is not validated if the algorithm of the presented token is set to "none". This allows an attacker to connect to Pulsar instances as any user (incl. admins).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Pulsar· Apachemaven
95%
v < 2.7.1Apache Pulsar ≤ v < 2.7.1
Affected range stops below 2.7.1, so it looks safe — our inference, not a vendor statement

References (8)

x_refsource_MISCMailing ListVendor Advisory
Source: [email protected]
https://lists.apache.org/thread.html/r347650d15a3e9c5f58b83e918b6ad6dedc2a63d3eb63da8e6a7be87e%40%3Cusers.pulsar.apache.org%3E
Mailing Listx_refsource_MLIST
Source: [email protected]
https://lists.apache.org/thread.html/r8e545559781231a83bf0644548c660255859e52feb86bbfcd42590da%40%3Cdev.pulsar.apache.org%3E
Mailing Listx_refsource_MLISTVendor Advisory
Source: [email protected]
https://lists.apache.org/thread.html/r9a12b4da2f26ce9b8f7e7117a879efaa973dab7e54717bbc7923fab1%40%3Cdev.pulsar.apache.org%3E
Mailing Listx_refsource_MLIST
Source: [email protected]
https://lists.apache.org/thread.html/ra49cb62105154e4795b259c79a6b27d63bfa2ab5787ff8529b089550%40%3Cdev.pulsar.apache.org%3E
Mailing Listx_refsource_MLIST
Source: [email protected]
https://lists.apache.org/thread.html/ra49cb62105154e4795b259c79a6b27d63bfa2ab5787ff8529b089550%40%3Cusers.pulsar.apache.org%3E
Mailing Listx_refsource_MLIST
Source: [email protected]
https://lists.apache.org/thread.html/rbe845aa1573a61769b9c5916c62971f4b10de87c2ea5f38a97f0cf84%40%3Cdev.pulsar.apache.org%3E
Mailing Listx_refsource_MLIST
Source: [email protected]
https://lists.apache.org/thread.html/rca54f4b26ba5e6f2e39732b47ec51640e89f57e3b6a38ac3bab314df%40%3Cdev.pulsar.apache.org%3E
Mailing Listx_refsource_MLIST
Source: [email protected]
https://lists.apache.org/thread.html/rf2e90942996dceebac8296abf39257cfeb5ae918f82f7af3d37a48c5%40%3Cdev.pulsar.apache.org%3E

CVSS

9.8CRITICAL[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-347

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