Red Hat Bugzilla – Bug 146882
SSH allows attacker to divine root password
Last modified: 2007-11-30 17:06:54 EST
*** This bug has been split off bug 141642 for RHEL2.1 *** ------- Original comment by George Toft on 2004.12.02 12:52 ------- From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322) Description of problem: With openssh configured to not allow remote root login (file: /etc/ssh/sshd_config, PermitRootLogin no), an attempt to log in remotely as root with the wrong password results in a 3 second delay followed by: Permission denied, please try again. If the correct password is entered, there is no delay before presenting the message: Permission denied, please try again. An attacker could measure the time between rejections with an attack tool and determine the root password. Version-Release number of selected component (if applicable): 3.1p1-14 How reproducible: Always Steps to Reproduce: 1. Set "PermitRootLogin no" in /etc/ssh/sshd_config 2. Restart sshd: service sshd restart 3. From remote machine, attempt remote login to server. Alternately, ssh localhost. 4. Enter bogus password - view error after 3 seconds. 5. Enter correct password - view error immediately with no delay. Actual Results: no delay presented when correct password is entered Expected Results: 3 second delay before presenting "Permission denied, please try again." Additional info:
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2005-481.html