Exim Header Syntax Checking Remote Stack Buffer Overrun Vulnerability

BID:10291

Info

Exim Header Syntax Checking Remote Stack Buffer Overrun Vulnerability

Bugtraq ID: 10291
Class: Boundary Condition Error
CVE: CVE-2004-0400
Remote: Yes
Local: No
Published: May 06 2004 12:00AM
Updated: Jul 12 2009 04:07AM
Credit: Discovery is credited to Georgi Guninski.
Vulnerable: University of Cambridge Exim-tls 3.35
+ Debian Linux 3.0 sparc
 + Debian Linux 3.0 s/390
 + Debian Linux 3.0 ppc
 + Debian Linux 3.0 mipsel
 + Debian Linux 3.0 mips
 + Debian Linux 3.0 m68k
 + Debian Linux 3.0 ia-64
 + Debian Linux 3.0 ia-32
 + Debian Linux 3.0 hppa
 + Debian Linux 3.0 arm
 + Debian Linux 3.0 alpha
 + Debian Linux 3.0
University of Cambridge Exim 4.32
University of Cambridge Exim 3.35
+ Debian Linux 3.0 sparc
 + Debian Linux 3.0 s/390
 + Debian Linux 3.0 ppc
 + Debian Linux 3.0 mipsel
 + Debian Linux 3.0 mips
 + Debian Linux 3.0 m68k
 + Debian Linux 3.0 ia-64
 + Debian Linux 3.0 ia-32
 + Debian Linux 3.0 hppa
 + Debian Linux 3.0 arm
 + Debian Linux 3.0 alpha
 + Debian Linux 3.0
Not Vulnerable: University of Cambridge Exim 4.32

Discussion

Exim Header Syntax Checking Remote Stack Buffer Overrun Vulnerability

Exim is reportedly prone to a remotely exploitable stack-based buffer overrun vulnerability.

This issue is exposed if header syntax checking has been enabled in the agent and may be triggered by a malicious e-mail. Though not confirmed to be exploitable, if this condition were to be exploited, it would result in execution of arbitrary code in the context of the mail transfer agent. Otherwise, the agent would crash when handling malformed syntax in an e-mail message.

The issue is reported to exist in both Exim 3.35 and 4.32, though the vulnerable code exists in different source files in each of these versions.

It should be noted that the vulnerable functionality is not enabled in the default install, though some Linux/Unix distributions that ship the software may enable it.

Exploit / POC

Exim Header Syntax Checking Remote Stack Buffer Overrun Vulnerability

Proof-of-concept code that triggers a denial of service is available at the following location:
http://www.guninski.com/exim1.html

(note: there are separate proof-of-concepts for Exim 3.35 and 4.32.)

Solution / Fix

Exim Header Syntax Checking Remote Stack Buffer Overrun Vulnerability

Solution:
Debian has released advisory DSA-501-1 dealing with this and other issues. Please see the referenced web advisory for more information and details on obtaining fixes.

Debian has released advisory DSA 502-1 dealing with this issue for their Exim-tls packages. Please see the referenced web advisory for more information and details on obtaining fixes.

Gentoo has released advisory GLSA 200405-07 dealing with this issue. They have recommended taking the following actions:

All users of Exim should upgrade to the latest stable version:

# emerge sync

# emerge -pv ">=net-mail/exim-4.33-r1"
# emerge ">=net-mail/exim-4.33-r1"

Please see the referenced advisory for more information.

Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.


University of Cambridge Exim-tls 3.35

University of Cambridge Exim 3.35

References

Exim Header Syntax Checking Remote Stack Buffer Overrun Vulnerability

References:

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report