Sun Microsystems' Solaris 10 operating system has been hit by an
unpatched vulnerability in its telnet service, the server and
software vendor
warned.
Telnet is command prompt controlled network protocol that can be
used to on intranets and the internet. It was one of the early
internet standards but has fallen in disuse for its limited
security.
The flaw allows any user who accesses the telnet service for an
affected system to gain unauthorized access and execute commands
with the same privileges as local users. If a system is configured
to allow root access through telnet, the attacker will receive the
same security clearings.
Users can protect themselves against the vulnerability by disabling
all telnet traffic within Solaris or by blocking port 23 on their
firewalls. If telnet access is required, they can also change the
software's settings to prevent attackers from gaining root
access.
Danish security website Secunia rated the vulnerability as
"moderately critical", its third highest severity level on a five
step scale.
Sun Microsystems engineer Alan Hargreaves who investigated the bug
for the vendor on his blog apologized.
"Let me acknowledge that, yes, this was an almighty cock up and
should not have happened. It did happen. Let's move on," Hargreaves
wrote.
He added that a patch is under development and will be released
shortly
.