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Bug 322665 (CVE-2010-2023) - <mail-mta/exim-4.72: DoS/PrivEsc ('hardlink' vulnerability) (CVE-2010-{2023,2024})
Summary: <mail-mta/exim-4.72: DoS/PrivEsc ('hardlink' vulnerability) (CVE-2010-{2023,2...
Alias: CVE-2010-2023
Product: Gentoo Security
Classification: Unclassified
Component: Vulnerabilities (show other bugs)
Hardware: All Linux
: High normal (vote)
Assignee: Gentoo Security
Whiteboard: A3 [glsa]
Depends on: 325645
  Show dependency tree
Reported: 2010-06-03 18:37 UTC by Alex Legler (RETIRED)
Modified: 2014-01-27 12:37 UTC (History)
3 users (show)

See Also:
Package list:
Runtime testing required: ---


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Description Alex Legler (RETIRED) archtester gentoo-dev Security 2010-06-03 18:37:15 UTC
Quoting $URL by Dan Rosenberg:

Two vulnerabilities have been discovered in Exim 4, a popular mail transfer
agent used on Unix-like systems (

1. When Exim is used with a world-writable mail directory with the sticky-bit
set, local users may create hard links to other non-root users' files at the
expected location of those users' mailboxes, causing their files to be written
to upon mail delivery.  This could be used to create denial-of-service
conditions or potentially escalate privileges to those of targeted users.  This
issue has been assigned CVE-2010-2023.

2. When MBX locking is enabled, local users may exploit a race condition to
change permissions of other non-root users' files, leading to denial-of-service
conditions or potentially privilege escalation, or to create new files owned by
other users in unauthorized locations.  This issue has been assigned


Exim has released a new version, 4.72, available for download at  Vulnerable users are
advised to download and recompile from source, or request updated packages from
downstream distributions.
Comment 1 Fabian Groffen gentoo-dev 2010-06-03 19:05:02 UTC
I'll try to put exim-4.72 in the tree today or tomorrow.
Comment 2 Alex Legler (RETIRED) archtester gentoo-dev Security 2010-06-03 19:32:03 UTC
Updated package is in the tree. Grobian will be testing it for a few days and report back.
Comment 3 Fabian Groffen gentoo-dev 2010-06-05 05:50:19 UTC
It runs smoothly for me here.  I haven't seen any irregularities, feels good to me.
Comment 4 Alex Legler (RETIRED) archtester gentoo-dev Security 2010-06-08 19:02:11 UTC
Arches, please test and mark stable:
Target keywords : "alpha amd64 hppa ia64 ppc ppc64 sparc x86"
Comment 5 Andreas Schürch gentoo-dev 2010-06-09 12:56:33 UTC
Tested on x86, looks good over here.
Comment 6 Paweł Hajdan, Jr. (RETIRED) gentoo-dev 2010-06-09 13:13:43 UTC
x86 stable, thanks Andreas!
Comment 7 Jeroen Roovers (RETIRED) gentoo-dev 2010-06-10 01:47:15 UTC
Stable for HPPA.
Comment 8 Raúl Porcel (RETIRED) gentoo-dev 2010-06-13 14:19:49 UTC
alpha/ia64/sparc stable
Comment 9 Matthias Geerdsen (RETIRED) gentoo-dev 2010-06-14 22:31:11 UTC
CVE-2010-2023 (
  transports/appendfile.c in Exim before 4.72, when a world-writable
  sticky-bit mail directory is used, does not verify the st_nlink field
  of mailbox files, which allows local users to cause a denial of
  service or possibly gain privileges by creating a hard link to
  another user's file.

CVE-2010-2024 (
  transports/appendfile.c in Exim before 4.72, when MBX locking is
  enabled, allows local users to change permissions of arbitrary files
  or create arbitrary files, and cause a denial of service or possibly
  gain privileges, via a symlink attack on a lockfile in /tmp/.

Comment 10 Fabian Groffen gentoo-dev 2010-06-21 06:38:50 UTC
@amd64: please stabilise exim-4.72.  I'm running amd64 (without issues), so you should be good to go.
Comment 11 Markus Meier gentoo-dev 2010-06-21 20:35:04 UTC
amd64 stable
Comment 12 DEMAINE Benoît-Pierre, aka DoubleHP 2010-06-26 01:00:29 UTC
Markus: see bug 325645 : it does not build on AMD64 for me.
Comment 13 Brent Baude (RETIRED) gentoo-dev 2010-07-08 20:23:02 UTC
ppc64 done
Comment 14 Joe Jezak (RETIRED) gentoo-dev 2010-07-18 20:49:35 UTC
Marked ppc stable.
Comment 15 Stefan Behte (RETIRED) gentoo-dev Security 2010-08-01 12:31:07 UTC
glsa request filed.
Comment 16 Stefan Behte (RETIRED) gentoo-dev Security 2010-12-11 16:55:56 UTC
The remote code exec bug is fixed in >=4.70 ( but was initially not regarded as a security problem according to heise.

@net-mail: please punt <4.70.

Comment 17 Fabian Groffen gentoo-dev 2010-12-11 22:10:25 UTC
versions <4.70 dropped
Comment 18 GLSAMaker/CVETool Bot gentoo-dev 2014-01-27 12:37:02 UTC
This issue was resolved and addressed in
 GLSA 201401-32 at
by GLSA coordinator Mikle Kolyada (Zlogene).