[ SOURCE: http://www.secureroot.com/security/advisories/9735372633.html ] File deletion and other bugs in Auction Weaver LITE 1.0 - 1.04 -------------------------------------------------------------- Title: File deletion and other bugs in Auction Weaver LITE 1.0 - 1.04 Author: Steve Christey (coley@mitre.org) Date Published: October 16, 2000 Product Name: Auction Weaver LITE Affected Versions: 1.0 through 1.04 Affected Operating Systems: Unix and Windows NT Product URL: http://www.cgiscriptcenter.com/awl/ Vendor Name: CGI Script Center Vendor URL: http://www.cgiscriptcenter.com/ Vendor Email: support@cgiscriptcenter.com Impact: delete and read arbitrary files Remotely Exploitable: yes Locally Exploitable: no Patch Available: yes Patched Version: Auction Weaver 1.05 Patch URL: http://www.cgiscriptcenter.com/awl/ Bugtraq ID's: 1782, 1783 http://www.securityfocus.com/bid/1782 http://www.securityfocus.com/bid/1783 CVE Candidate Numbers: CAN-2000-0810, CAN-2000-0811 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2000-0810 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2000-0811 Description ----------- Auction Weaver LITE is a CGI program written in Perl. It allows users to create and host auctions on their web site. Auction Weaver LITE 1.0 through 1.04 was discovered to contain several vulnerabilities that allow remote attackers to create, read, or delete arbitrary files with the privileges of the Auction Weaver process. These vulnerabilities are different than the ones described by Meliksah Ozoral and teleh0r in several Bugtraq posts during August 2000 [see references below]. All of the vulnerabilities are commonly found in CGI scripting programs. These vulnerabilities were successfully exploited using a default installation of Auction Weaver on a Solaris 7 box. However, all platforms are vulnerable. The vendor has been notified and a patch is available. Solution -------- Auction Weaver 1.05 fixes all of the vulnerabilities described in this advisory. Upgrade to Auction Weaver 1.05 at: http://www.cgiscriptcenter.com/awl/ A complete workaround is not possible for the arbitrary file deletion problem, so users should upgrade to version 1.05. Additional Vulnerability Details -------------------------------- These vulnerabilities were discovered while attempting to determine whether CGI Script Center had patched the previously announced vulnerabilities. (While some acknowledgement was posted on the vendor's web site, it did not provide sufficient details to be certain that all of the identified problems had been fixed). The Common Vulnerabilities and Exposures (CVE) project has assigned unique names to each of these vulnerabilities. They are candidates for inclusion in the CVE list, which standardizes names for security problems. See http://cve.mitre.org/ The Security Focus VulnHelp service has also assigned Bugtraq ID's to these vulnerabilities. See http://www.securityfocus.com/vdb/ 1) File/directory deletion with malicious form field names containing .. CVE candidate: CAN-2000-0810 Bugtraq ID: 1782 In Auction Weaver 1.0 through 1.04, a remote attacker can delete arbitrary directories, and files within them, with the privileges of the Auction Weaver process. This vulnerability is due to a lack of sanity checking of the names of the form fields. Due to the nature of the bug, files can be deleted outside of the web document root using .. notation. Even if the filenames were properly cleansed of .. problems, however, non-administrators would still be able to delete auction information, because the vulnerable function is not password protected. The extent of this vulnerability is slightly mitigated by the fact that if the targeted directory contains subdirectories, the script may fail once it attempts to delete that subdirectory. However, it may have deleted other files before reaching that subdirectory. 2) Arbitrary file reading and creation with .. in username and bidfile CVE candidate: CAN-2000-0811 Bugtraq ID: 1783 In Auction Weaver 1.0 through 1.04, a remote attacker can read and create arbitrary files in arbitrary directories with the same privileges as the Auction Weaver process. The attacker can not fully control the contents of the file. The vulnerable script does not properly cleanse two form fields (username and bidfile) whose values are later used in constructing file pathnames. These form fields are different than those described in previous Bugtraq posts, but it is the same kind of vulnerability. An attacker can insert a .. into the field's value to access files outide of the data directory. The scope of the problem would be limited to file names with .dat extensions, except the program is written in Perl and does not filter out null characters. Thus the attacker can insert a null character at the end of the filename as specified in the form, effectively bypassing the .dat extension that is later appended to the filename. 3) Incomplete patching of catdir and fromfile .. vulnerabilities CVE candidate: CAN-2000-0686 (already assigned) Bugtraq ID: 1630 Auction Weaver 1.04 does not completely fix the .. vulnerabilities in the "catdir" and "fromfile" form fields, which was described by Meliksah Ozoral in a Bugtraq post on August 23, 2000 [1]. As originally described, these fields allowed file reading; however, they also allow file deletion. In version 1.04, the regular expression for removing ".." from filenames is not properly specified. Only files in the parent of the data directory can be read or deleted. However, in the default installation of Auction Weaver, the parent directory includes the server script itself. The script itself could be deleted, or the administrative password could be read from it. References ---------- The following vulnerabilities were discovered in earlier versions of Auction Weaver. They are listed here to distinguish them from the new vulnerabilities discussed in this advisory. [1] Directory traversal in version 1.02 via catdir form field. Bugtraq post by Meliksah Ozoral on August 23, 2000, titled "Auction WeaverT LITE 1.0" (subject is also listed as "=?iso-8859-9?Q?Auction_WeaverT_LITE_1.0?=" in some archives) URL: http://www.securityfocus.com/archive/1/78458 Bugtraq ID: 1630 CVE candidate name: CAN-2000-0690 [2] Execute commands with shell metacharacters in fromfile form field in version 1.02. Bugtraq post by teleh0r on August 30, 2000, titled "More problems with Auction Weaver & CGI Script Center." URL: http://www.securityfocus.com/archive/1/79452 Bugtraq ID: 1645 CVE candidate name: CAN-2000-0687 Disclosure Process ------------------ These vulnerabilities were disclosed to the vendor, and to the public, with guidance from Rain Forest Puppy's Issue disclosure policy (aka RFPolicy) at http://www.wiretrip.net/rfp/policy.html. In addition, this advisory follows emerging best practices for the responsible disclosure of new vulnerability information. 1) VENDOR NOTIFICATION Email was sent to the vendor at the suggested email addresses referenced in RFPolicy, i.e.: securityalert, secure, security, support, and info@cgiscriptcenter.com. The email provided all known details of the vulnerabilities, including exploits and fixes. A brief alert was also submitted to the online contact web page. The subject header included the phrase "Serious security vulnerabilities." The email included contact information such as name, title, organization, and phone number. Guidance was provided to the vendor to ensure that the vulnerabilities were properly patched. 2) PUBLIC NOTIFICATION Public announcement of the vulnerabilities was delayed until the vendor had a patch available and its customers were notified. This advisory includes commonly used identifiers (Bugtraq ID's and CVE candidate names) to support cross-referencing and to distinguish these vulnerabilities from others. The Security Focus VulnHelp service was consulted to obtain the Bugtraq ID's. For more information or assistance in drafting advisories, please email vulnhelp@securityfocus.com. 3) LEVEL OF DETAIL Sufficient technical details are provided in this advisory so that security researchers and system administrators can understand the nature of the problems and distinguish them from similar problems. Exploit code is not included with this advisory. However, all exploit materials were provided to the vendor. Event Log --------- Sep 16, 2000: - initial discovery - notified vendor - email to support@cgiscriptcenter.com and others - short post to the online contact form Sep 18, 2000: - Vendor responded from both contact points (on the next business day). Additional details provided to vendor - Vendor disabled downloads for the vulnerable software Sep 20, 2000: - Sent email to vendor requesting a status update - Received a response that the vendor is still working on fixes Sep 21, 2000: - Vendor email that problems have been fixed, requested clarification - Sent clarification Sep 22, 2000: - Vendor submitted new version for review - Sent additional feedback Sep 23, 2000: - Vendor completed fixes, sent for final review Sep 25, 2000: - Final review complete - Vendor released new version - Advisory written and sent to vendor for review - Obtained CVE candidate names for advisory Sep 26, 2000: - Advisory approved by vendor Oct 5, 2000: - Advisory submitted to VulnHelp for review and Bugtraq ID's Oct 12, 2000: - Bugtraq ID's obtained from VulnHelp Oct 16, 2000: - Advisory submitted to Bugtraq, NTBugtraq, and CERT/CC