COMMAND
getdoc.cgi
SYSTEMS AFFECTED
Some Infonautics' applications.
PROBLEM
Following was found by Black Watch Labs. Some Infonautics'
applications utilize the getdoc.cgi CGI in such a way that allows
attackers to gain (read) access to a document they would otherwise
have to pay in order to view.
The exact mechanism of getdoc.cgi is not clear to the authors of
this advisory, yet what is known is as following. This CGI is
used by Infonautics' applications in order to view/purchase
documents in archives and alike sites. The CGI is called with
several parameters, and there are probably several "modes" and/or
defaults (for missing parameters). However, it was observed that
when the CGI is called in the following manner:
getdoc.cgi?id=whatever-this&OIDS=whatever-that&Form=RL
or
getdoc.cgi?id=whatever-this&OIDS=whatever-that&Form=RL&m=1
Then it is possible to remove the "RL" value from the "Form"
field, and the application will grant access to the document
without going through the payment phase.
As the mechanism implemented in getdoc.cgi is not fully
understood, it is possible that links having the above format
will not be vulnerable, and it may also be possible that links
which do not conform to the above format will be vulnerable.
As noted above, if a link is encountered in the following format:
getdoc.cgi?id=whatever-this&OIDS=whatever-that&Form=RL&m=1
Then an attacker can remove the RL and send:
getdoc.cgi?id=whatever-this&OIDS=whatever-that&Form=&m=1
SOLUTION
No patch or workaround available at the time of this release.