Executive Summary

Summary
Title Exim alternate configuration privilege escalation vulnerability
Informations
Name VU#758489 First vendor Publication 2010-12-13
Vendor VU-CERT Last vendor Modification 2010-12-13
Severity (Vendor) N/A Revision M

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
 
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:M/Au:N/C:C/I:C/A:C)
Cvss Base Score 6.9 Attack Range Local
Cvss Impact Score 10 Attack Complexity Medium
Cvss Expoit Score 3.4 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

Vulnerability Note VU#758489

Exim alternate configuration privilege escalation vulnerability

Overview

A vulnerability in the way that the Exim mail server handles configuration files may allow a local attacker to gain escalated privileges on an affected system.

I. Description

Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet. If Exim is built without specifying the ALT_CONFIG_ROOT_ONLY configuration option, then the Exim user can invoke Exim with an arbitrary configuration file. The Exim developers note that this option is unspecified by default. Consequently, any ${run...} directives specified in that configuration file will be executed as root.

Note: this vulnerability has been reported being exploited in the wild.

II. Impact

A local attacker with the ability to execute commands as the Exim user may be able to execute code with root privileges.

III. Solution

We are currently unaware of a practical solution to this problem.

Ensure that Exim is built with the ALT_CONFIG_ROOT_ONLY option enabled

The Exim developers note that this may result in a loss of functionality in certain cases where more than one configuration is in use. Specifically, the exim user will no longer be permitted to invoke Exim with an alternative configuration file and have it executed with root privileges.

Vendor Information

VendorStatusDate NotifiedDate Updated
SUSE LinuxAffected2010-12-13

References

http://www.exim.org/lurker/message/20101207.215955.bb32d4f2.en.html
http://bugs.exim.org/show_bug.cgi?id=1044
https://bugzilla.redhat.com/show_bug.cgi?id=662012
http://lists.exim.org/lurker/message/20101209.172233.abcba158.en.html
http://lists.exim.org/lurker/message/20101213.140800.7c3bae4b.en.html

Credit

This vulnerability was discovered as a result of its exploitation in the wild. Sergey Kononenko provided confirmation and public analysis.

This document was written by Chad R Dougherty.

Other Information

Date Public:2010-12-07
Date First Published:2010-12-13
Date Last Updated:2010-12-13
CERT Advisory: 
CVE-ID(s):CVE-2010-4345
NVD-ID(s):CVE-2010-4345
US-CERT Technical Alerts: 
Severity Metric:13.54
Document Revision:5

Original Source

Url : http://www.kb.cert.org/vuls/id/758489

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-264 Permissions, Privileges, and Access Controls

OVAL Definitions

Definition Id: oval:org.mitre.oval:def:12720
 
Oval ID: oval:org.mitre.oval:def:12720
Title: DSA-2131-1 exim4 -- arbitrary code execution
Description: Several vulnerabilities have been found in exim4 that allow a remote attacker to execute arbitrary code as root user. Exploits for these issues have been seen in the wild. This update fixes a memory corruption issue that allows a remote attacker to execute arbitrary code as the Debian-exim user. A fix for an additional issue that allows the Debian-exim user to obtain root privileges is currently being checked for compatibility issues. It is not yet included in this upgrade but will released soon in an update to this advisory. For the stable distribution, this problem has been fixed in version 4.69-9+lenny1. This advisory only contains the packages for the alpha, amd64, hppa, i386, ia64, powerpc, and s390 architectures. The packages for the arm, armel, mips, mipsel, and sparc architectures will be released as soon as they are built. For the testing distribution and the unstable distribution, this problem has been fixed in version 4.70-1. We strongly recommend that you upgrade your exim4 packages.
Family: unix Class: patch
Reference(s): DSA-2131-1
CVE-2010-4344
CVE-2010-4345
 Version: 5
Platform(s): Debian GNU/Linux 5.0
 Product(s): exim4
Definition Synopsis:
Definition Id: oval:org.mitre.oval:def:21735
 
Oval ID: oval:org.mitre.oval:def:21735
Title: RHSA-2011:0153: exim security update (Moderate)
Description: Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, as demonstrated by the spool_directory directive.
Family: unix Class: patch
Reference(s): RHSA-2011:0153-01
CESA-2011:0153
CVE-2010-4345
 Version: 4
Platform(s): Red Hat Enterprise Linux 5
CentOS Linux 5
 Product(s): exim
Definition Synopsis:
Definition Id: oval:org.mitre.oval:def:22839
 
Oval ID: oval:org.mitre.oval:def:22839
Title: ELSA-2011:0153: exim security update (Moderate)
Description: Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, as demonstrated by the spool_directory directive.
Family: unix Class: patch
Reference(s): ELSA-2011:0153-01
CVE-2010-4345
 Version: 6
Platform(s): Oracle Linux 5
 Product(s): exim
Definition Synopsis:

CPE : Common Platform Enumeration

TypeDescriptionCount
Application 69

ExploitDB Exploits

id Description
2010-12-16 Exim4 <= 4.69 string_format Function Heap Buffer Overflow

OpenVAS Exploits

Date Description
2012-07-30 Name : CentOS Update for exim CESA-2011:0153 centos4 x86_64
File : nvt/gb_CESA-2011_0153_exim_centos4_x86_64.nasl
2012-07-30 Name : CentOS Update for exim CESA-2011:0153 centos5 x86_64
File : nvt/gb_CESA-2011_0153_exim_centos5_x86_64.nasl
2011-08-09 Name : CentOS Update for exim CESA-2011:0153 centos5 i386
File : nvt/gb_CESA-2011_0153_exim_centos5_i386.nasl
2011-02-11 Name : Ubuntu Update for exim4 vulnerabilities USN-1060-1
File : nvt/gb_ubuntu_USN_1060_1.nasl
2011-01-31 Name : CentOS Update for exim CESA-2011:0153 centos4 i386
File : nvt/gb_CESA-2011_0153_exim_centos4_i386.nasl
2011-01-24 Name : FreeBSD Ports: exim
File : nvt/freebsd_exim1.nasl
2011-01-21 Name : RedHat Update for exim RHSA-2011:0153-01
File : nvt/gb_RHSA-2011_0153-01_exim.nasl
2011-01-04 Name : SuSE Update for exim SUSE-SA:2010:059
File : nvt/gb_suse_2010_059.nasl

Open Source Vulnerability Database (OSVDB)

Id Description
69860 Exim exim User Account Configuration File Directive Local Privilege Escalation

Exim contains a flaw that may allow an attacker to gain access to unauthorized privileges. The issue is triggered when an attacker leverages the ability of an exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, allowing a local attacker to gain root privileges.

Nessus® Vulnerability Scanner

Date Description
2014-06-13 Name : The remote openSUSE host is missing a security update.
File : suse_11_3_exim-101211.nasl - Type : ACT_GATHER_INFO
2014-01-28 Name : The remote Gentoo host is missing one or more security-related patches.
File : gentoo_GLSA-201401-32.nasl - Type : ACT_GATHER_INFO
2013-07-12 Name : The remote Oracle Linux host is missing one or more security updates.
File : oraclelinux_ELSA-2011-0153.nasl - Type : ACT_GATHER_INFO
2012-08-01 Name : The remote Scientific Linux host is missing one or more security updates.
File : sl_20110117_exim_on_SL4_x.nasl - Type : ACT_GATHER_INFO
2011-05-05 Name : The remote openSUSE host is missing a security update.
File : suse_11_1_exim-101211.nasl - Type : ACT_GATHER_INFO
2011-05-05 Name : The remote openSUSE host is missing a security update.
File : suse_11_2_exim-101211.nasl - Type : ACT_GATHER_INFO
2011-02-11 Name : The remote Ubuntu host is missing one or more security-related patches.
File : ubuntu_USN-1060-1.nasl - Type : ACT_GATHER_INFO
2011-01-31 Name : The remote Debian host is missing a security-related update.
File : debian_DSA-2154.nasl - Type : ACT_GATHER_INFO
2011-01-28 Name : The remote CentOS host is missing one or more security updates.
File : centos_RHSA-2011-0153.nasl - Type : ACT_GATHER_INFO
2011-01-18 Name : The remote Red Hat host is missing one or more security updates.
File : redhat-RHSA-2011-0153.nasl - Type : ACT_GATHER_INFO
2011-01-10 Name : The remote FreeBSD host is missing a security-related update.
File : freebsd_pkg_e4fcf020044711e0becc0022156e8794.nasl - Type : ACT_GATHER_INFO
2010-12-15 Name : The remote service has a buffer overflow.
File : exim_string_vformat.nasl - Type : ACT_ATTACK
2010-12-12 Name : The remote Debian host is missing a security-related update.
File : debian_DSA-2131.nasl - Type : ACT_GATHER_INFO