Vulnerability Note VU#579928

diffutils sdiff creates temporary files insecurely

Original Release date: 09 Oct 2001 | Last revised: 08 Nov 2001


diffutils, a set of utilities distributed with many versions of linux, contains a utility called sdiff, which creates temporary files of predictable names in an insecure fashion. Using a symbolic link attack, an intruder can cause overwrite of any file writable by the user executing sdiff.


sdiff creates temporary files as part of the file comparison process. Under some conditions, sdiff will create files in /tmp with predictable names, and furthermore does not check for prior existence or ownership of these files.


By creating a series of symbolic links, an intruder can cause sdiff to overwrite any file writable by the user executing sdiff, which may corrupt data or deny service.


Apply vendor patches; see the Systems Affected section below.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
CalderaAffected18 Sep 200119 Sep 2001
ImmunixAffected10 Jan 200117 Sep 2001
MandrakeSoftAffected10 Jan 200117 Sep 2001
RedHatAffected18 Sep 200108 Nov 2001
TrustixAffected10 Jan 200118 Sep 2001
DebianUnknown18 Sep 200109 Oct 2001
SequentUnknown18 Sep 200109 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



This vulnerability was first described by Greg Kroah-Hartman of Immunix.

This document was last modified by Tim Shimeall.

Other Information

  • CVE IDs: CAN-2001-0117
  • Date Public: 10 Jan 2001
  • Date First Published: 09 Oct 2001
  • Date Last Updated: 08 Nov 2001
  • Severity Metric: 4.50
  • Document Revision: 15


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