During a pen-test we have notice how is easy to identify valid users on vulnerable systems, through a simple timing attack.
When I try to connect to ftp without ssl using a unreal user with bad password I get
immediatly response of incorrect login, when I use real user with bad
password I get 2 second of wait before get message of incorrect login.
It seems to be very nice to the recent CAN-2003-0190 about OpenSSH/PAM timing attack allows remote users identification
I have tested this on Linux RH 7.3 and RH 8.0
I belive the vulnerability is easy to exploit and may have high severity, if combined with poor password policies and other security problems that allow local privilege escalation.
Alessandro Fiorenzi
a.fiorenzi@infogroup.it aka netexpress
*------------------------------------------------------------------------ INFOGROUP S.P.A http://www.infogroup.it
------------------------------------------------------------------------- DR. FIORENZI ALESSANDRO *
Consulente Tribunale Firenze - sicurezza informatica -
System Administrator
Socio CLUSIT <file:///home/fiore/signature/www.clusit.it>, ALSI <file:///home/fiore/signature/www.alsi.it>
Tel : +39.055.43.65.742 CE : +39.335.64.144.77 @Email : a.fiorenzi@infogroup.it PGP Key: http://www.infogroup.it/ds/fiorenzi.asc
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*"Faber est suae quisque fortunae" *
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