Line printer software the weakest link

Security experts have warned that network managers may have overlooked multiple vulnerabilities in implementations of line printer systems software.

Researchers at the Computer Emergency Response Team (Cert) Co-ordination Center said the problems related to buffer overflow issues that allowed remote users to gain root access to servers.

According to Cert, the vulnerabilities, which surround software packages known as internet security scanners, exist in the line printer daemon, which enables various clients to share printers over a network.

The vulnerabilities could allow intruders to gain root privileges and launch denial-of-service attacks through IBM AIX, FreeBSD, NetBSD and OpenBSD line printers and Hewlett Packard's HP-UX line printers.

In its warning, Cert said that, even though some of the problems had been previously disclosed, it believes administrators "may have overlooked one or more of these vulnerabilities".

As specific problems Cert mentioned BSD line printer daemon buffer overflow in displayq, IBM's AIX line printer daemon buffer overflow in kill_print, send_status and chk_fhost, and HP's HP-UX line printer daemon buffer overflow.

Patches are available for some of the vulnerabilities and a more detailed explanation can be found on Cert's advisory page.