The open_log function in log.c in Exim 4.72 and earlier does not check the return value from (1) setuid or (2) setgid system calls, which allows local users to append log data to arbitrary files via a symlink attack.

Exim was updated to verify the return value of the setuid/setgid calls now. (CVE-2011-0017: CVSS v2 Base Score: 6.9 (AV:L/AC:M/Au:N/C:C/I:C/A:C): Link Following (CWE-59))

The remote host is affected by the vulnerability described in GLSA-201401-32 (Exim: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Exim. Please review the       CVE identifiers referenced below for details.
  Impact :

    A remote attacker could possibly execute arbitrary code with root       privileges, or cause a Denial of Service condition.
  Workaround :

    There is no known workaround at this time.

exim.org reports :

CVE-2011-0017 - check return value of setuid/setgid. This is a privilege escalation vulnerability whereby the Exim run-time user can cause root to append content of the attacker's choosing to arbitrary files.

It was discovered that Exim contained a design flaw in the way it processed alternate configuration files. An attacker that obtained privileges of the 'Debian-exim' user could use an alternate configuration file to obtain root privileges. (CVE-2010-4345)

It was discovered that Exim incorrectly handled certain return values when handling logging. An attacker that obtained privileges of the 'Debian-exim' user could use this flaw to obtain root privileges.
(CVE-2011-0017)

Dan Rosenberg discovered that Exim incorrectly handled writable sticky-bit mail directories. If Exim were configured in this manner, a local user could use this flaw to cause a denial of service or possibly gain privileges. This issue only applied to Ubuntu 6.06 LTS, 8.04 LTS, 9.10, and 10.04 LTS. (CVE-2010-2023)

Dan Rosenberg discovered that Exim incorrectly handled MBX locking. If Exim were configured in this manner, a local user could use this flaw to cause a denial of service or possibly gain privileges. This issue only applied to Ubuntu 6.06 LTS, 8.04 LTS, 9.10, and 10.04 LTS.
(CVE-2010-2024).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote host is running Exim, a message transfer agent.

According to the version number in its banner, the installed version of Exim is earlier than 4.74 and thus potentially affected by a local privilege escalation vulnerability.

If the remote host is running Linux, attackers can exploit this issue to append arbitrary data to files through symbolic link attacks.
Successfully exploiting this issue allows local attackers with 'exim' run-time user privileges to perform certain actions with superuser privileges, leading to a complete compromise of an affected computer.

The remote host is running Exim, a message transfer agent. 

Versions of Exim earlier than 4.74 are potentially affected by a local privilege escalation vulnerability.  Attackers can exploit this flaw to append arbitrary data to files through symbolic link attacks.  Successfully exploiting this issue allows local attackers with 'exim' run-time privileges to perform certain actions with superuser privileges, leading to a complete compromise of an affected computer.  Note that this issue only affects Exim on Linux.

A design flaw (CVE-2010-4345 ) in exim4 allowed the local Debian-exim user to obtain root privileges by specifying an alternate configuration file using the -C option or by using the macro override facility (-D option). Unfortunately, fixing this vulnerability is not possible without some changes in exim4's behaviour. If you use the -C or -D options or use the system filter facility, you should evaluate the changes carefully and adjust your configuration accordingly. The Debian default configuration is not affected by the changes.

The detailed list of changes is described in the NEWS.Debian file in the packages. The relevant sections are also reproduced below.

In addition to that, missing error handling for the setuid/setgid system calls allowed the Debian-exim user to cause root to append log data to arbitrary files (CVE-2011-0017 ).

ID	Name	Product	Family	Severity
75482	openSUSE Security Update : exim (openSUSE-SU-2011:0105-1)	Nessus	SuSE Local Security Checks	medium
72159	GLSA-201401-32 : Exim: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
53716	openSUSE Security Update : exim (openSUSE-SU-2011:0105-1)	Nessus	SuSE Local Security Checks	medium
51963	FreeBSD : exim -- local privilege escalation (44ccfab0-3564-11e0-8e81-0022190034c0)	Nessus	FreeBSD Local Security Checks	medium
51954	Ubuntu 6.06 LTS / 8.04 LTS / 9.10 / 10.04 LTS / 10.10 : exim4 vulnerabilities (USN-1060-1)	Nessus	Ubuntu Local Security Checks	medium
51861	Exim < 4.74 Local Privilege Escalation	Nessus	SMTP problems	medium
5752	Exim < 4.74 Local Privilege Escalation Vulnerability	Nessus Network Monitor	SMTP Servers	high
51819	Debian DSA-2154-1 : exim4 - privilege escalation	Nessus	Debian Local Security Checks	medium

Detections

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CVE-2011-0017

critical

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medium

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medium

medium

medium

medium

high

medium