Authorization Bypass Through User-Controlled Key vulnerability in Apache ZooKeeper
Critical9.1CVE-2023-44981 · Published Oct 11, 2023 · updated Sep 10, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| org.apache.zookeeper:zookeeper Maven | < 3.7.2 | 3.7.2 |
| >= 3.8.0, < 3.8.3 | 3.8.3 | |
| >= 3.9.0, < 3.9.1 | 3.9.1 |
Details and references
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.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-639
- Also known as
- BIT-zookeeper-2023-44981, CVE-2023-44981
- nvd.nist.gov/vuln/detail/CVE-2023-44981
- github.com/apache/zookeeper
- lists.apache.org/thread/wf0yrk84dg1942z1o74kd8nycg6pgm5b
- lists.debian.org/debian-lts-announce/2023/10/msg00029.html
- security.netapp.com/advisory/ntap-20240621-0007
- www.debian.org/security/2023/dsa-5544
- www.openwall.com/lists/oss-security/2023/10/11/4
More Apache ZooKeeper advisories
All Apache ZooKeeper| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Mar 152024 | Apache ZooKeeper vulnerable to information disclosure in persistent watchers handling CVE-2024-23944Medium5.3fixed in 3.8.4, 3.9.2 | Medium5.3 | 3.8.4, 3.9.2 |
| Nov 72024 | Apache ZooKeeper: Authentication bypass with IP-based authentication in Admin Server CVE-2024-51504Highfixed in 3.9.3 | High | 3.9.3 |
| May 132022 | Uncontrolled Resource Consumption in Apache ZooKeeper CVE-2017-5637High7.5fixed in 3.4.10, 3.5.3 | High7.5 | 3.4.10, 3.5.3 |
| May 132022 | Missing Authorization in Apache ZooKeeper CVE-2018-8012High7.5fixed in 3.4.10, 3.5.4-beta | High7.5 | 3.4.10, 3.5.4-beta |
| Sep 242025 | Apache ZooKeeper: Insufficient Permission Check in AdminServer Snapshot/Restore Commands CVE-2025-58457Medium4.3fixed in 3.9.4 | Medium4.3 | 3.9.4 |
| Mar 7 | Apache ZooKeeper: Reverse-DNS fallback enables hostname verification bypass in ZooKeeper ZKTrustManager CVE-2026-24281High7.4fixed in 3.8.6, 3.9.5 | High7.4 | 3.8.6, 3.9.5 |