[ GLSA 202105-03 ] GPT fdisk: Integer underflow

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Gentoo Linux Security Advisory                           GLSA 202105-03
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                                            https://security.gentoo.org/
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  Severity: Normal
     Title: GPT fdisk: Integer underflow
      Date: May 26, 2021
      Bugs: #768762
        ID: 202105-03

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Synopsis
========

An integer underflow in sgdisk from GPT fdisk package might allow local
attacker(s) to escalate privileges.

Background
==========

GPT fdisk (consisting of the gdisk, cgdisk, sgdisk, and fixparts
programs) is a set of text-mode partitioning tools for Linux, FreeBSD,
Mac OS X, and Windows.

Affected packages
=================

     -------------------------------------------------------------------
      Package              /     Vulnerable     /            Unaffected
     -------------------------------------------------------------------
   1  sys-apps/gptfdisk            < 1.0.6                    >= 1.0.6

Description
===========

It was discovered that ReadLogicalParts() function in basicmbr.cc was
missing a bounds check.

Impact
======

A local attacker could entice a user to insert a malicious formatted
block device (USB stick or SD card for example), that, when processed
with sgdisk, possibly resulting in local escalation of privileges or a
Denial of Service condition.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All GPT fdisk users should upgrade to the latest version:

   # emerge --sync
   # emerge --ask --oneshot --verbose ">=sys-apps/gptfdisk-1.0.6"

References
==========

[ 1 ] CVE-2021-0308
       https://nvd.nist.gov/vuln/detail/CVE-2021-0308

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

  https://security.gentoo.org/glsa/202105-03

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
[email protected] or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
=======

Copyright 2021 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5