{"id":"UBUNTU-CVE-2017-5637","details":"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.","modified":"2026-04-22T11:27:46.636547Z","published":"2017-10-10T01:30:00Z","related":["USN-4789-1"],"upstream":["CVE-2017-5637"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2017-5637"},{"type":"REPORT","url":"https://issues.apache.org/jira/browse/ZOOKEEPER-2693"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2017-5637"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4789-1"}],"affected":[{"package":{"name":"zookeeper","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/zookeeper@3.4.5+dfsg-1ubuntu0.1~esm1?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.5+dfsg-1ubuntu0.1~esm1"}]}],"versions":["3.4.5+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"libzookeeper-java"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"libzookeeper-mt2"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"libzookeeper-st2"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"libzookeeper2"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"python-zookeeper"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"zookeeper"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"zookeeper-bin"},{"binary_version":"3.4.5+dfsg-1ubuntu0.1~esm1","binary_name":"zookeeperd"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2017/UBUNTU-CVE-2017-5637.json"}},{"package":{"name":"zookeeper","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/zookeeper@3.4.8-1ubuntu0.1~esm1?arch=source&distro=esm-apps/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.8-1ubuntu0.1~esm1"}]}],"versions":["3.4.6-8","3.4.7-1","3.4.8-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"libzookeeper-java"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"libzookeeper-mt2"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"libzookeeper-st2"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"libzookeeper2"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"python-zookeeper"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"zookeeper"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"zookeeper-bin"},{"binary_version":"3.4.8-1ubuntu0.1~esm1","binary_name":"zookeeperd"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2017/UBUNTU-CVE-2017-5637.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}