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Fencer Intel
critical 9.8

CVE-2021-22160 in the critical feed json

Authentication with JWT allows use of “none”-algorithm

published 5y ago modified 4mo ago also GHSA-3cv4-xxv7-934q , EUVD-2021-1254

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
52.9%
EPSS 52.9% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

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).

Patch / fix

  • maven org.apache.pulsar:pulsar 2.7.2
  • Apache Software Foundation Apache Pulsar 2.7.1

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Exploit prediction

52.93% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.pulsar:pulsar
<2.7.2
2.7.2

Affected products

  • Apache Software Foundation Apache Pulsar

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.