OpenCA Security Advisory: Cross Site Scripting vulnerability

2004-09-06T00:00:00
ID SECURITYVULNS:DOC:6755
Type securityvulns
Reporter Securityvulns
Modified 2004-09-06T00:00:00

Description

OpenCA Security Advisory: Cross Site Scripting vulnerability

Authors Martin Bartosch <mb-bugtraq@cynops.de> Michael Bell <michael.bell@cms.hu-berlin.de>

2004-09-01 Initial revision 2004-09-06 Public release

Summary

The OpenCA Project is a collaborative effort to develop a robust, full-featured and Open Source out-of-the-box Certification Authority implementing the most used protocols with full-strength cryptography world-wide. OpenCA is based on many Open-Source Projects. Among the supported software is OpenLDAP, OpenSSL, Apache Project, Apache mod_ssl.

A Cross Site Scripting (XSS) vulnerability was found in the OpenCA PKI software, allowing users of the system to inject malicious HTML code into the system. The malicious code may even affect offline components.

Affected versions

All versions of OpenCA, including 0.9.1-8 and 0.9.2 RC6.

Details

Form input to the web frontends is not properly validated, making it possible to inject malicious HTML code into the system. Once the offending code has been inserted into the system, it may affect PKI staff or other users accessing the data.

OpenCA advocates the separation between individual frontends and the use of an offline CA and RA. In this case data is exchanged using a removable medium such as a floppy disk. The offending code embedded in the user data may thus be transferred even to systems not connected to a network and might be used to attack offline nodes.

Impact

Cross site scripting attacks primarily affect the client system running the browser used to display the web page. OpenCA itself is not directly affected by such attacks. However, XSS exploit code may be deployed e. g. in order to gain session credentials, allowing for session takeover. More advanced attacks (requiring specially crafted exploit code) could even be targeted at manipulating data on the OpenCA node on the user's behalf.

Recommendations

All users of OpenCA should upgrade to a version that is not affected by the problem.

OpenCA version 0.9.1 users are encouraged to upgrade to version 0.9.1-9. Users of the current development branch 0.9.2 should upgrade to CVS head.

References

The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0787 to this issue.

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0787

URL for this Security Advisory: http://www.openca.org/news/CAN-2004-0787.txt

Appendix

Security Patches

Patches against version 0.9.2

Index: src/common/lib/functions/initServer

RCS file: /cvsroot/openca/openca-0.9/src/common/lib/functions/initServer,v retrieving revision 1.40 diff -u -r1.40 initServer --- src/common/lib/functions/initServer 30 Aug 2004 12:31:53 -0000 1.40 +++ src/common/lib/functions/initServer 1 Sep 2004 13:27:27 -0000 @@ -184,6 +184,10 @@ $query->set_gettext (\&i18nGettext); close ($fh);

  • validate input data

  • 2004-08-27 Martin Bartosch <m.bartosch@cynops.de>

  • validateCGIParameters(\$query); + ## reinit configuration my $CONFIG = $AUTOCONF {"etc_prefix"}.'/servers/'.$AUTOCONF {"config_prefix"}.'.conf'; if( not defined (my $ret = $config->loadCfg( "$CONFIG" )) ) { Index: src/common/lib/functions/misc-utils.lib =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/common/lib/functions/misc-utils.lib,v retrieving revision 1.50 diff -u -r1.50 misc-utils.lib --- src/common/lib/functions/misc-utils.lib 26 Aug 2004 14:08:03 -0000 1.50 +++ src/common/lib/functions/misc-utils.lib 1 Sep 2004 13:27:27 -0000 @@ -443,4 +443,39 @@ debug ($cmd, @_); }

+# 2004-08-31 Martin Bartosch <m.bartosch@cynops.de> +# clean up CGI parameters +# input: reference to CGI class instance +# This function modifies the object itself +sub validateCGIParameters { + my $queryref = shift; +
+ ## validate input data + ## 2004-08-27 Martin Bartosch <m.bartosch@cynops.de> + foreach my $param (keys %{$$queryref->Vars}) { + my @values = $$queryref->param($param); + + # replace < and > with < and &rt; for all CGI parameters passed + # NOTE/FIXME: unescaping might be necessary when actually + # passing this data to e. g. certificate generation routines + # to prevent literal XML entities in certificate contents + map { + s/</</gm; + s/>/>/gm; + } @values; + $$queryref->param(-name => $param, -value => @values); + + # extra sanity check just to be sure (redundant) + foreach (@values) { + if (/<\S+.*?>/m) { + print "Content-type: text/html\n\n"; + print "Security violation\n"; + exit 101; + } + } + } + return $queryref; +} + + 1;

Patches against version 0.9.1-8

Index: src/common/lib/functions/misc-utils.lib

RCS file: /cvsroot/openca/openca-0.9/src/common/lib/functions/misc-utils.lib,v retrieving revision 1.16.2.2 diff -u -r1.16.2.2 misc-utils.lib --- src/common/lib/functions/misc-utils.lib 16 Apr 2003 13:24:51 -0000 1.16.2.2 +++ src/common/lib/functions/misc-utils.lib 1 Sep 2004 11:49:14 -0000 @@ -445,4 +445,38 @@

}

+# 2004-08-31 Martin Bartosch <m.bartosch@cynops.de> +# clean up CGI parameters +# input: reference to CGI class instance +# This function modifies the object itself +sub validateCGIParameters { + my $queryref = shift; +
+ ## validate input data + ## 2004-08-27 Martin Bartosch <m.bartosch@cynops.de> + foreach my $param (keys %{$$queryref->Vars}) { + my @values = $$queryref->param($param); + + # replace < and > with < and &rt; for all CGI parameters passed + # NOTE/FIXME: unescaping might be necessary when actually + # passing this data to e. g. certificate generation routines + # to prevent literal XML entities in certificate contents + map { + s/</</gm; + s/>/>/gm; + } @values; + $$queryref->param(-name => $param, -value => @values); + + # extra sanity check just to be sure (redundant) + foreach (@values) { + if (/<\S+.*?>/m) { + print "Content-type: text/html\n\n"; + print "Security violation\n"; + exit 101; + } + } + } + return $queryref; +} + 1; Index: src/web-interfaces/ca/ca.in =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/web-interfaces/ca/ca.in,v retrieving revision 1.8.2.1 diff -u -r1.8.2.1 ca.in --- src/web-interfaces/ca/ca.in 10 Nov 2003 13:10:48 -0000 1.8.2.1 +++ src/web-interfaces/ca/ca.in 1 Sep 2004 11:49:16 -0000 @@ -132,6 +132,9 @@ ##// Now it's time to get the parameters passed over the web $query = new OpenCA::TRIStateCGI;

+## validate input parameters +validateCGIParameters(\$query); + ## Generate a new reference to Configuration ( instance ) $dbconfig = new OpenCA::Configuration; $dbiconfig = new OpenCA::Configuration; Index: src/web-interfaces/ldap/ldap.in =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/web-interfaces/ldap/ldap.in,v retrieving revision 1.7.2.1 diff -u -r1.7.2.1 ldap.in --- src/web-interfaces/ldap/ldap.in 10 Nov 2003 13:10:48 -0000 1.7.2.1 +++ src/web-interfaces/ldap/ldap.in 1 Sep 2004 11:49:16 -0000 @@ -138,6 +138,9 @@ ##// Now it's time to get the parameters passed over the web $query = new OpenCA::TRIStateCGI;

+## validate input parameters +validateCGIParameters(\$query); + ## Generate a new reference to Configuration ( instance ) $dbconfig = new OpenCA::Configuration; $dbiconfig = new OpenCA::Configuration; Index: src/web-interfaces/node/node.in =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/web-interfaces/node/node.in,v retrieving revision 1.2.2.1 diff -u -r1.2.2.1 node.in --- src/web-interfaces/node/node.in 10 Nov 2003 13:10:48 -0000 1.2.2.1 +++ src/web-interfaces/node/node.in 1 Sep 2004 11:49:17 -0000 @@ -139,6 +139,9 @@ ##// Now it's time to get the parameters passed over the web $query = new OpenCA::TRIStateCGI;

+## validate input parameters +validateCGIParameters(\$query); + ## Generate a new reference to Configuration ( instance ) $dbconfig = new OpenCA::Configuration; $dbiconfig = new OpenCA::Configuration; Index: src/web-interfaces/pub/pki.in =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/web-interfaces/pub/pki.in,v retrieving revision 1.7.2.1 diff -u -r1.7.2.1 pki.in --- src/web-interfaces/pub/pki.in 10 Nov 2003 13:10:48 -0000 1.7.2.1 +++ src/web-interfaces/pub/pki.in 1 Sep 2004 11:49:17 -0000 @@ -136,6 +136,9 @@ ##// Now it's time to get the parameters passed over the web $query = new OpenCA::TRIStateCGI;

+## validate input parameters +validateCGIParameters(\$query); + ## Generate a new reference to Configuration ( instance ) $dbconfig = new OpenCA::Configuration; $dbiconfig = new OpenCA::Configuration; Index: src/web-interfaces/pub/scepd.in =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/web-interfaces/pub/Attic/scepd.in,v retrieving revision 1.2.2.1 diff -u -r1.2.2.1 scepd.in --- src/web-interfaces/pub/scepd.in 10 Nov 2003 13:10:48 -0000 1.2.2.1 +++ src/web-interfaces/pub/scepd.in 1 Sep 2004 11:49:17 -0000 @@ -121,6 +121,9 @@ ##// Now it's time to get the parameters passed over the web $query = new OpenCA::TRIStateCGI;

+## validate input parameters +validateCGIParameters(\$query); + ## Generate a new reference to Configuration ( instance ) $dbconfig = new OpenCA::Configuration; $dbiconfig = new OpenCA::Configuration; Index: src/web-interfaces/ra/RAServer.in =================================================================== RCS file: /cvsroot/openca/openca-0.9/src/web-interfaces/ra/RAServer.in,v retrieving revision 1.8.2.1 diff -u -r1.8.2.1 RAServer.in --- src/web-interfaces/ra/RAServer.in 10 Nov 2003 13:10:49 -0000 1.8.2.1 +++ src/web-interfaces/ra/RAServer.in 1 Sep 2004 11:49:18 -0000 @@ -138,6 +138,9 @@ ##// Now it's time to get the parameters passed over the web $query = new OpenCA::TRIStateCGI;

+## validate input parameters +validateCGIParameters(\$query); + ## Generate a new reference to Configuration ( instance ) $dbconfig = new OpenCA::Configuration; $dbiconfig = new OpenCA::Configuration;

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