Gecko [ paroquia-rio-de-mouro.pt ]

Linux anchor 4.4.0-210-generic #242-Ubuntu SMP Fri Apr 16 09:57:56 UTC 2021 x86_64
Apache/2.4.18 (Ubuntu)
Server IP : 10.10.100.4 & Your IP : 216.73.217.150
Domains : Cant Read [ /etc/named.conf ]
User : www-data

Name	Size	Permission	Date
README.Debian	1.12 KB	-rw-r--r--	2015-10-02 15:34
changelog.Debian.gz	2.2 KB	-rw-r--r--	2015-10-23 23:11
copyright	4.26 KB	-rw-r--r--	2015-10-02 15:34

Rename

Please check http://www.friedhoff.org/posixfilecaps.html to get more
information on POSIX File Capabilities.

Example: how to remove the SUID root bit from /bin/ping?
--------------------------------------------------------

Make sure you have kernel 2.6.24 or newer you have
CONFIG_SECURITY_CAPABILITIES and CONFIG_SECURITY_FILE_CAPABILITIES
enabled. The Debian kernels are fine.

$ ls -l /bin/ping
  -rwsr-xr-x 1 root root 30736 2007-01-31 00:10 /bin/ping
     ^
That is not good.

$ sudo chmod 755 /bin/ping

Or use dpkg-statoverride.

$ ls -l /bin/ping
  -rwxr-xr-x 1 root root 30736 2007-01-31 00:10 /bin/ping

That is better but ping fails.

$ ping -c1 localhost
  ping: icmp open socket: Operation not permitted

Now set the missing capability:

$ sudo setcap cap_net_raw+ep /bin/ping

... and ping will work again.

$ ping -c1 localhost
  PING localhost (127.0.0.1) 56(84) bytes of data.
  64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.026 ms

--- localhost ping statistics ---
  1 packets transmitted, 1 received, 0% packet loss, time 0ms
  rtt min/avg/max/mdev = 0.026/0.026/0.026/0.000 ms

Torsten Werner