Vulnerability Note VU#465971

BSCW vulnerable to arbitrary file overwriting via symlink redirection of temporary file

Original Release date: 15 Nov 2001 | Last revised: 15 Nov 2001

Overview

BSCW is a groupware system that runs on a web server. BSCW follows symbolic links in tar files that it extracts into a user's local area. Accessing those links may allow the user to view arbitrary files viewable by the web server, and to overwrite files writable by the web server.

Description

BSCW provides for a number of upload and download options, plus on-line access to documents via a "data bag" (a local area for each user). One of the features supported by BSCW is extraction of uploaded tar files into the "data bag." Reportedly, when a tar file containing symbolic links is extracted into the "data bag", BSCW will support access to the linked object under the web server's userid.

Impact

By creating symbolic links to files on the web server and placing them in a tar file, then extracting them into the "data bag," an attacker reportedly could view any file readable by the web server. By modifying these files via BSCW, the attacker may be able to overwrite files writable by the web server. Directly uploading symbolic

links will not work as the BSCW software either refuses this upload with an error message or hangs on the upload.

Solution

Apply vendor patches; see the Systems Affected section below.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
BSCW.gmdAffected16 Jul 200101 Oct 2001
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A

References

Credit

This vulnerability was first described on the Bugtraq mailing list.

This document was last modified by Tim Shimeall.

Other Information

  • CVE IDs: Unknown
  • Date Public: 24 Aug 2001
  • Date First Published: 15 Nov 2001
  • Date Last Updated: 15 Nov 2001
  • Severity Metric: 4.72
  • Document Revision: 14

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