ZooKeeper SASL Auth Bypass via Optional Instance ID Fixed in 3.9.1/3.8.3/3.7.2
CVE-2023-44981 Published on October 11, 2023
Apache ZooKeeper: Authorization bypass in SASL Quorum Peer Authentication
Authorization Bypass Through User-Controlled Key vulnerability in Apache ZooKeeper. If SASL Quorum Peer authentication is enabled in ZooKeeper (quorum.auth.enableSasl=true), the authorization is done by verifying that the instance part in SASL authentication ID is listed in zoo.cfg server list. The instance part in SASL auth ID is optional and if it's missing, like 'eve@EXAMPLE.COM', the authorization check will be skipped. As a result an arbitrary endpoint could join the cluster and begin propagating counterfeit changes to the leader, essentially giving it complete read-write access to the data tree. Quorum Peer authentication is not enabled by default.
Users are recommended to upgrade to version 3.9.1, 3.8.3, 3.7.2, which fixes the issue.
Alternately ensure the ensemble election/quorum communication is protected by a firewall as this will mitigate the issue.
See the documentation for more details on correct cluster administration.
Vulnerability Analysis
CVE-2023-44981 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is an Insecure Direct Object Reference / IDOR Vulnerability?
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CVE-2023-44981 has been classified to as an Insecure Direct Object Reference / IDOR vulnerability or weakness.
Products Associated with CVE-2023-44981
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Affected Versions
Apache Software Foundation Apache ZooKeeper:- Version 3.9.0 and below 3.9.1 is affected.
- Version 3.8.0, <= 3.8.2 is affected.
- Version 3.7.0, <= 3.7.1 is affected.
- Before 3.7.0 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.