Short Name |
APP:MISC:GUESTBOOK-CGI |
---|---|
Severity |
Minor |
Recommended |
No |
Recommended Action |
Drop |
Category |
APP |
Keywords |
Guestbook CGI Remote Command Execution |
Release Date |
2012/08/31 |
Update Number |
2181 |
Supported Platforms |
idp-4.0+, isg-3.0+, j-series-9.5+, mx-11.4+, srx-12.1+, srx-branch-12.1+, vmx-17.4+, vsrx-12.1+, vsrx3bsd-18.2+ |
This signature detects attempts to exploit a known vulnerability against Guestbook CGI. A successful attack can lead to arbitrary code execution.
When Guestbook is configured to allow HTML posts and you have enabled server-side includes for HTML, it may be possible for an attacker to embed SSI (server-side include) code in guestbook messages. The server-side includes allow for remote command execution, including displaying of any files to which the web server has read access (see the example): <!--#exec cmd="cat /etc/group" In an attempt to stop this from happening, guestbook.pl parses for SSI commands under the assumption that they are in this format: <-- SSI command --> ^^ Does not need to be there. Apache will accept different formats, which can evade the regular expression in guestbook.pl, executing commands on the target host as they would [if they were put there by the author].