Hello,
I got an issue with one of my CentOS box. It has a high cpu utilization on vsftpd, can someone shed some light why is the vsftpd causes the high cpu load? (multiple processess running and need fine-tuning?)
[root@xxxxxx ~]# cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)
PID SYSCPU USRCPU VGROW RGROW RDDSK WRDSK RUID EUID ST EXC THR S CPUNR CPU CMD 1/407
19802 0.38s 2.17s 0K 0K - - ggdlx02u - NE 0 0 E - 26% <vsftpd>
26858 0.26s 1.51s 0K 0K - - ggdlx02u - NE 0 0 E - 18% <vsftpd>
28400 0.20s 1.17s 74576K 1328K 0K 0K ggdlx02u ggdlx02u N- - 1 R 1 14% vsftpd
1837 0.01s 1.29s 0K 0K 0K 0K root root -- - 1 S 2 13% rngd
22695 0.20s 1.10s 0K 0K - - ggdlx02u - NE 0 0 E - 13% <vsftpd>
1 [#####################################*************100.0%] Tasks: 4830, 681 thr; 4 running
2 [####################################**************100.0%] Load average: 55.38 45.77 42.57
3 [##########################************************100.0%] Uptime: 24 days, 15:17:04
4 [#######################################***********100.0%]
Mem[|||||||||||||||||||||||||||||||||||||||||||||25.9G/31.3G]
Swp[||||||||| 604M/4.00G]
PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command
2622 ggdlx02uc 20 0 74576 1328 860 R 28.8 0.0 0:00.70 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
32008 ggdlx02uc 20 0 90592 1416 880 R 28.2 0.0 0:01.29 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
5121 ggdlx02uc 20 0 90592 1424 888 R 16.9 0.0 0:00.30 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
1837 root 20 0 90500 1596 1500 R 13.0 0.0 16h13:06 /sbin/rngd -f
5748 ggdlx02uc 20 0 74576 1328 860 R 7.9 0.0 0:00.14 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
5757 ggdlx02uc 20 0 74580 1324 860 R 7.9 0.0 0:00.14 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
17605 root 20 0 123M 6300 1496 R 7.3 0.0 0:01.09 htop
26222 ggdlx02td 20 0 134M 18680 1052 S 1.7 0.1 0:03.16 find /local/home/ggdlx02tdba/comms/outtray/2019 /local/home/g
[root@xxxxxx ~]# cat /etc/vsftpd/vsftpd.conf
# Example config file /etc/vsftpd/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=YES
#
# Uncomment this to allow local users to log in.
# When SELinux is enforcing check for SE bool ftp_home_dir
local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
# When SELinux is enforcing check for SE bool allow_ftpd_anon_write, allow_ftpd_full_access
#anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
dirmessage_enable=YES
#
# Activate logging of uploads/downloads.
xferlog_enable=YES
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# You may override where the log file goes if you like. The default is shown
# below.
#xferlog_file=/var/log/xferlog
#
# If you want, you can have your log file in standard ftpd xferlog format.
# Note that the default log file location is /var/log/xferlog in this case.
xferlog_std_format=YES
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120
#
# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
#nopriv_user=ftpsecure
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode. The vsftpd.conf(5) man page explains
# the behaviour when these options are disabled.
# Beware that on some FTP servers, ASCII support allows a denial of service
# attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
# predicted this attack and has always been safe, reporting the size of the
# raw file.
# ASCII mangling is a horrible feature of the protocol.
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
#ftpd_banner=Welcome to blah FTP service.
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/etc/vsftpd/banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
# (Warning! chroot'ing can be very dangerous. If using chroot, make sure that
# the user does not have write access to the top level directory within the
# chroot)
#chroot_local_user=YES
#chroot_list_enable=YES
# (default follows)
#chroot_list_file=/etc/vsftpd/chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
#ls_recurse_enable=YES
#
# When "listen" directive is enabled, vsftpd runs in standalone mode and
# listens on IPv4 sockets. This directive cannot be used in conjunction
# with the listen_ipv6 directive.
listen=NO
#
# This directive enables listening on IPv6 sockets. By default, listening
# on the IPv6 "any" address (::) will accept connections from both IPv6
# and IPv4 clients. It is not necessary to listen on *both* IPv4 and IPv6
# sockets. If you want that (perhaps because you want to listen on specific
# addresses) then you must run two copies of vsftpd with two configuration
# files.
# Make sure, that one of the listen options is commented !!
listen_ipv6=YES
pam_service_name=vsftpd
userlist_enable=YES
tcp_wrappers=YES
Can someone help me out to make a thorough investigation on this issue. Many thanks
High Cpu utilization on vsftpd
Re: High Cpu utilization on vsftpd
Start by reading the logs it writes and see if someone is hacking into it by brute force attack.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
Re: High Cpu utilization on vsftpd
i checked the logs, no malicious events. Transaction is coming from internal server. Corporate firewall is enabled.