{"id":"UBUNTU-CVE-2015-5600","details":"The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.","modified":"2026-02-04T04:26:55.705366Z","published":"2015-08-02T00:00:00Z","related":["USN-2710-1"],"upstream":["CVE-2015-5600"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2015-5600"},{"type":"REPORT","url":"http://seclists.org/fulldisclosure/2015/Jul/92"},{"type":"REPORT","url":"https://kingcope.wordpress.com/2015/07/16/openssh-keyboard-interactive-authentication-brute-force-vulnerability-maxauthtries-bypass/"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-2710-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2015-5600"}],"affected":[{"package":{"name":"openssh","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:6.6p1-2ubuntu2.2?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.6p1-2ubuntu2.2"}]}],"versions":["1:6.2p2-6","1:6.2p2-6ubuntu1","1:6.4p1-1","1:6.4p1-2","1:6.5p1-1","1:6.5p1-2","1:6.5p1-3","1:6.5p1-4","1:6.5p1-6","1:6.6p1-1","1:6.6p1-2","1:6.6p1-2ubuntu1","1:6.6p1-2ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_version":"1:6.6p1-2ubuntu2.2","binary_name":"openssh-client"},{"binary_version":"1:6.6p1-2ubuntu2.2","binary_name":"openssh-server"},{"binary_version":"1:6.6p1-2ubuntu2.2","binary_name":"openssh-sftp-server"},{"binary_version":"1:6.6p1-2ubuntu2.2","binary_name":"ssh"},{"binary_version":"1:6.6p1-2ubuntu2.2","binary_name":"ssh-askpass-gnome"},{"binary_version":"1:6.6p1-2ubuntu2.2","binary_name":"ssh-krb5"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2015/UBUNTU-CVE-2015-5600.json"}}],"schema_version":"1.7.3","severity":[{"type":"Ubuntu","score":"low"}]}