CVE-2023-44981

CVE-2023-44981 is a critical-severity vulnerability in Apache Zookeeper with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Description

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 '[email protected]', 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.

Frequently asked questions

What is CVE-2023-44981?
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 '[email protected]', 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.
How severe is CVE-2023-44981?
CVE-2023-44981 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2023-44981 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-44981?
CVE-2023-44981 primarily affects Apache Zookeeper. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-44981?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-44981 published?
CVE-2023-44981 was published on 2023-10-11 and last updated on 2026-06-17.

References

Affected products (5)

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