Zookeeper
CVE-2017-5637
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication required for critical functions
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. EPSS exploitation probability: 17.45%. |
| Exploit ScenarioDerived | A remote attacker could access critical functionality without authentication by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and EPSS exploitation probability 17.4%.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Require authentication for all sensitive operations, implement defense in depth.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in maven
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Missing Authentication for Critical Function (CWE-306), which allows attackers to access critical functionality without authentication. Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests. Apache ZooKeeper thru version 3.4.9 and 3.5.2 suffer from this issue, fixed in 3.4.10, 3.5.3, and later. Affected products include: Apache Zookeeper, Debian Debian Linux. Version information: version 3.4.9.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
Two four letter word commands "wchp/wchc" are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests. Apache ZooKeeper thru version 3.4.9 and 3.5.2 suffer from this issue, fixed in 3.4.10, 3.5.3, and later.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Exploit-DB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Affected Products (CPE)CVE.org
Buffer overflow in the C cli shell in Apache Zookeeper before 3.4.9 and 3.5.x before 3.5.3, when using the "cmd:" batch
Hostname verification bypass in Apache ZooKeeper's ZKTrustManager allows attackers with a valid certificate trusted by t
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable h
When using IPAuthenticationProvider in ZooKeeper Admin Server there is a possibility of Authentication Bypass by Spoofin
Authorization Bypass Through User-Controlled Key vulnerability in Apache ZooKeeper. Rated critical severity (CVSS 9.1),
Authorization bypass in Apache ZooKeeper 3.8.0 through 3.8.6 and 3.9.0 through 3.9.5 lets remote attackers delete empty
Unauthenticated remote clients can discover the names of ACL-restricted znodes in Apache ZooKeeper 3.8.0 through 3.8.6 a
Improper certificate hostname validation in Apache ZooKeeper's quorum TLS path allows a CA-trusted peer certificate whos
Apache ZooKeeper 3.8.5 and 3.9.4 improperly log sensitive client configuration data at INFO level, allowing unauthentica
No authentication/authorization is enforced when a server attempts to join a quorum in Apache ZooKeeper before 3.4.10, a
An issue is present in Apache ZooKeeper 1.0.0 to 3.4.13 and 3.5.0-alpha to 3.5.4-beta. Rated medium severity (CVSS 5.9),
Audit log injection in Apache ZooKeeper 3.9.0–3.9.5 and 3.8.0–3.8.6 allows attackers to forge entries in zookeeper_audit
GitHub PoC