The files in /proc directory are world-writable in CentOS. What are the effects of these permissions on the security of the Linux server? Is it ok to change their world-writable permissions? Executing the following command lists world writeable files.
find / -type f -perm -002 -ls | more
The files in the /proc directory are not real files because they are created automatically. They tell the OS where to find different settings and resources. One might also notice that they are all 0Kb in size. Changing their permissions won’t be a good idea because it could cause the system to break down.
Details of the first few files are given below.
[root@backup ~]# for i in `find / -type f -perm -002 -ls | awk '{print $NF}' | head` ; do echo ; echo $i ; echo; echo "file command output" ; file $i ; echo; echo "stat command output" ; stat $i ; echo; echo; done
/proc/sys/kernel/ns_last_pid
file command output
/proc/sys/kernel/ns_last_pid: empty
stat command output
File: /proc/sys/kernel/ns_last_pid
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 64893971 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:object_r:sysctl_kernel_ns_last_pid_t:s0
Access: 2022-09-17 07:18:31.975664037 +0200
Modify: 2022-09-17 07:18:31.975664037 +0200
Change: 2022-09-17 07:18:31.975664037 +0200
Birth: -
/proc/1/task/1/attr/current
file command output
/proc/1/task/1/attr/current: empty
stat command output
File: /proc/1/task/1/attr/current
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 21806 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-06-09 00:19:08.635093551 +0200
Modify: 2022-06-09 00:19:08.635093551 +0200
Change: 2022-06-09 00:19:08.635093551 +0200
Birth: -
/proc/1/task/1/attr/exec
file command output
/proc/1/task/1/attr/exec: empty
stat command output
File: /proc/1/task/1/attr/exec
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 64895079 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-09-17 07:18:31.995663792 +0200
Modify: 2022-09-17 07:18:31.995663792 +0200
Change: 2022-09-17 07:18:31.995663792 +0200
Birth: -
/proc/1/task/1/attr/fscreate
file command output
/proc/1/task/1/attr/fscreate: empty
stat command output
File: /proc/1/task/1/attr/fscreate
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 21810 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-06-09 00:19:09.033093554 +0200
Modify: 2022-06-09 00:19:09.033093554 +0200
Change: 2022-06-09 00:19:09.033093554 +0200
Birth: -
/proc/1/task/1/attr/keycreate
file command output
/proc/1/task/1/attr/keycreate: empty
stat command output
File: /proc/1/task/1/attr/keycreate
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 64895080 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-09-17 07:18:31.995663792 +0200
Modify: 2022-09-17 07:18:31.995663792 +0200
Change: 2022-09-17 07:18:31.995663792 +0200
Birth: -
/proc/1/task/1/attr/sockcreate
file command output
/proc/1/task/1/attr/sockcreate: empty
stat command output
File: /proc/1/task/1/attr/sockcreate
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 21968 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-06-09 00:19:09.903093562 +0200
Modify: 2022-06-09 00:19:09.903093562 +0200
Change: 2022-06-09 00:19:09.903093562 +0200
Birth: -
/proc/1/attr/current
file command output
/proc/1/attr/current: empty
stat command output
File: /proc/1/attr/current
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 1242 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-06-09 00:19:05.816999998 +0200
Modify: 2022-06-09 00:19:05.816999998 +0200
Change: 2022-06-09 00:19:05.816999998 +0200
Birth: -
/proc/1/attr/exec
file command output
/proc/1/attr/exec: empty
stat command output
File: /proc/1/attr/exec
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 64895287 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-09-17 07:18:31.998663755 +0200
Modify: 2022-09-17 07:18:31.998663755 +0200
Change: 2022-09-17 07:18:31.998663755 +0200
Birth: -
/proc/1/attr/fscreate
file command output
/proc/1/attr/fscreate: empty
stat command output
File: /proc/1/attr/fscreate
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 64895288 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-09-17 07:18:31.998663755 +0200
Modify: 2022-09-17 07:18:31.998663755 +0200
Change: 2022-09-17 07:18:31.998663755 +0200
Birth: -
/proc/1/attr/keycreate
file command output
/proc/1/attr/keycreate: empty
stat command output
File: /proc/1/attr/keycreate
Size: 0 Blocks: 0 IO Block: 1024 regular empty file
Device: 5h/5d Inode: 64895289 Links: 1
Access: (0666/-rw-rw-rw-) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:system_r:init_t:s0
Access: 2022-09-17 07:18:31.998663755 +0200
Modify: 2022-09-17 07:18:31.998663755 +0200
Change: 2022-09-17 07:18:31.998663755 +0200
Birth: -
