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shadow-utils useradd creates temporary files insecurely

Vulnerability Note VU#424080

Original Release Date: 2001-11-08 | Last Revised: 2001-11-08

Overview

Shadow-utils is an encryption and account management package freely distributed for many Linux implementations. The useradd program in this package creates insecure temporary files with predictable names in a write-protected directory. If this directory is changed to be writable, an attacker may be able to use a symbolic link attack to overwrite arbitrary files.

Description

The useradd program calls the passwd program, which stores temporary files with predictable names in /etc/default, a protected directory. The program does not check for prior existence or ownership of these files. Useradd normally runs with setuid root privileges.

Impact

If /etc/default is changed to be world-writable, an attacker may be able to create a symbolic link with predictable name, and point it to any writable file on the system. This may cause corruption of the file.

Solution

Apply vendor patches; see the Systems Affected section below.

Change /etc/default to not be world-writable.

Vendor Information

424080
Expand all

Immunix

Notified:  January 10, 2001 Updated:  October 04, 2001

Status

  Vulnerable

Vendor Statement

http://www.linuxsecurity.com/advisories/other_advisory-1034.html

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

MandrakeSoft

Notified:  January 10, 2001 Updated:  October 04, 2001

Status

  Vulnerable

Vendor Statement

http://www.linux-mandrake.com/en/updates/2001/MDKSA-2001-007.php3?dis=7.2

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Caldera

Notified:  October 09, 2001 Updated:  October 29, 2001

Status

  Not Vulnerable

Vendor Statement

None of our currently released Linux products contains world writeable /etc/default/ directory.
=> Not vulnerable.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Debian

Notified:  October 09, 2001 Updated:  November 08, 2001

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

IBM

Notified:  October 09, 2001 Updated:  November 08, 2001

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Sequent

Notified:  October 09, 2001 Updated:  November 08, 2001

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

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

References

Credit

This vulnerability was first reported by Greg Kroah-Hartman

This document was last modified by Tim Shimeall.

Other Information

CVE IDs: CVE-2001-0120
Severity Metric: 0.30
Date Public: 2001-01-10
Date First Published: 2001-11-08
Date Last Updated: 2001-11-08 18:19 UTC
Document Revision: 10

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