CyberSecBulletin
CVE-2023-30428NVD status: Modified

Apache Pulsar Broker: Incorrect Authorization

CVE-2023-30428 is a high-severity incorrect authorization vulnerability in Apache Pulsar Broker from Apache, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.10.4 as the first without the flaw, so updating Apache Pulsar Broker to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Apache Pulsar Broker to 2.10.4 or a later version.
  2. Read the advisory on lists.apache.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
ApacheApache Pulsar Broker2.9.0 through 2.9.5; 2.10.0 up to, but not including, 2.10.4; 2.11.02.10.4
Apachepulsar2.9.0 through 2.9.5; 2.10.0 through 2.10.4; 2.11.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.2HighCNA (apache.org)
CVSS 3.18.1HighNVD

Official description

Incorrect Authorization vulnerability in Apache Software Foundation Apache Pulsar Broker's Rest Producer allows authenticated user with a custom HTTP header to produce a message to any topic using the broker's admin role. This issue affects Apache Pulsar Brokers: from 2.9.0 through 2.9.5, from 2.10.0 before 2.10.4, 2.11.0. The vulnerability is exploitable when an attacker can connect directly to the Pulsar Broker. If an attacker is connecting through the Pulsar Proxy, there is no known way to exploit this authorization vulnerability. There are two known risks for affected users. First, an attacker could produce garbage messages to any topic in the cluster. Second, an attacker could produce messages to the topic level policies topic for other tenants and influence topic settings that could lead to exfiltration and/or deletion of messages for other tenants. 2.8 Pulsar Broker users and earlier are unaffected. 2.9 Pulsar Broker users should upgrade to one of the patched versions. 2.10 Pulsar Broker users should upgrade to at least 2.10.4. 2.11 Pulsar Broker users should upgrade to at least 2.11.1. 3.0 Pulsar Broker users are unaffected.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Incorrect Authorization vulnerabilities (CWE-863)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Incorrect Authorization vulnerabilities

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