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Sendmail Header Processing Buffer Overflow Vulnerability

Risk
High

Date Discovered
03-03-2003

Description
Sendmail is a widely used MTA for Unix and Microsoft Windows systems.

A remotely exploitable vulnerability has been discovered in Sendmail. The vulnerability is due to a buffer overflow condition in the SMTP header parsing component. Remote attackers may exploit this vulnerability by connecting to target SMTP servers and transmitting to them malformed SMTP data.

The overflow condition occurs when Sendmail processes incoming e-mail messages with multiple addresses in a field such as "From:" or "CC:". One of the checks to ensure that the addresses are valid is flawed, resulting in a buffer overflow condition. Successful attackers may exploit this vulnerability to gain root privileges on affected servers remotely.

Versions 5.2 to 8.12.7 are affected. Administrators are advised to upgrade to 8.12.8 or apply available patches to prior versions of the 8.x tree.

Intruder Alert
Symantec has released an Intruder Alert 3.5/3.6 Integration Policy for NetProwler 3.5x. Click here for more information.

A policy for Symantec Intruder Alert 3.6 is available here.

NetProwler
Symantec has released Security Update 23 for NetProwler 3.5.1, which includes a detection for attempts to exploit this vulnerability. Click here for more information.

Symantec Enterprise Firewall, Symantec VelociRaptor, and Symantec Gateway Security
All currently supported versions protect Sendmail servers against the recently announced Sendmail vulnerability by default. The attack violates parameters defined in the SMTP RFCs. The SMTPd module that provides full application inspection for the Simple Mail Transport Protocol strictly enforces SMTP RFCs. No patches or configuration changes to SMTPd are required to protect against this Sendmail exploit.

Enterprise Security Manager
Symantec Security Response has released an Enterprise Security Manager (ESM) policy for this vulnerability. Click here for further information.

Symantec ManHunt
On March 4, 2003, an exploit to this vulnerability was released by LSD (Last Stage of Delirium). Symantec ManHunt Protocol Anomaly Detection technology detects this specific exploit as "SMTP Malformed Data". Click here to view a screenshot of Symantec ManHunt detecting this exploit. Although Manhunt can detect the exploit with the Protocol Anomaly Detection technology, below is a custom rule that can be used in the Hybrid mode function for exact identification of the exploit.

*******************start file********************

alert tcp any any -> any 25 (msg:"SMTP_Sendmail_From_Overflow";
content:"<><><><><><><>"; reference:CAN-2002-1337; reference:BID 6991;)

*************EOF*********************
For more information on how to create custom signatures, refer to the "Symantec ManHunt Administrative Guide: Appendix A Custom Signatures for HYBRID Mode.

Components Affected
Sendmail Consortium Sendmail 8.12.7
Sendmail Consortium Sendmail 8.12.6

  • Apple MacOS X 10.2.4

Sendmail Consortium Sendmail 8.12.5
Sendmail Consortium Sendmail 8.12.4
Sendmail Consortium Sendmail 8.12.3
Sendmail Consortium Sendmail 8.12.2
  • Apple MacOS X 10.2.3
  • Apple MacOS X 10.2.2
  • Apple MacOS X 10.2.1
  • Apple MacOS X 10.2 (Jaguar)
  • Apple MacOS X Server 10.2.3
  • Apple MacOS X Server 10.2.2
  • Apple MacOS X Server 10.2.1
  • Apple MacOS X Server 10.2

Sendmail Consortium Sendmail 8.12.1
Sendmail Consortium Sendmail 8.12beta7
Sendmail Consortium Sendmail 8.12beta5
Sendmail Consortium Sendmail 8.12beta16
Sendmail Consortium Sendmail 8.12beta12
Sendmail Consortium Sendmail 8.12beta10
Sendmail Consortium Sendmail 8.12.0
Sendmail Consortium Sendmail 8.11.6
Sendmail Consortium Sendmail 8.11.5
Sendmail Consortium Sendmail 8.11.4
  • Conectiva Linux 7.0

Sendmail Consortium Sendmail 8.11.3
Sendmail Consortium Sendmail 8.11.2
  • RedHat Linux 7.1 ia64
  • RedHat Linux 7.1 i386
  • RedHat Linux 7.1 alpha
  • RedHat Linux 7.1

Sendmail Consortium Sendmail 8.11.1
  • Caldera OpenLinux Server 3.1
  • Caldera OpenLinux Workstation 3.1
  • Conectiva Linux 6.0

Sendmail Consortium Sendmail 8.11
  • RedHat Linux 7.0 sparc
  • RedHat Linux 7.0 i386
  • RedHat Linux 7.0 alpha
  • RedHat Linux 7.0
  • SCO Open Server 5.0.6a
  • SCO Open Server 5.0.6
  • SCO Open Server 5.0.5
  • SCO Open Server 5.0.4

Sendmail Consortium Sendmail 8.10.2
Sendmail Consortium Sendmail 8.10.1
Sendmail Consortium Sendmail 8.10
Sendmail Consortium Sendmail 8.9.3
  • SGI IRIX 6.5.18m
  • SGI IRIX 6.5.18f
  • SGI IRIX 6.5.17m
  • SGI IRIX 6.5.17f
  • SGI IRIX 6.5.16m
  • SGI IRIX 6.5.16f
  • SGI IRIX 6.5.15m
  • SGI IRIX 6.5.15f
  • SGI IRIX 6.5.14m
  • SGI IRIX 6.5.14f
  • SGI IRIX 6.5.13m
  • SGI IRIX 6.5.13f
  • SGI IRIX 6.5.12m
  • SGI IRIX 6.5.12f
  • SGI IRIX 6.5.11m
  • SGI IRIX 6.5.11f
  • SGI IRIX 6.5.10m
  • SGI IRIX 6.5.10f
  • SGI IRIX 6.5.9m
  • SGI IRIX 6.5.9f
  • SGI IRIX 6.5.8m
  • SGI IRIX 6.5.8f
  • SGI IRIX 6.5.7m
  • SGI IRIX 6.5.7f

Sendmail Consortium Sendmail 8.9.2
Sendmail Consortium Sendmail 8.9.1
Sendmail Consortium Sendmail 8.9.0
Sendmail Consortium Sendmail 8.8.8
  • SGI IRIX 6.5.6
  • SGI IRIX 6.5.5
  • SGI IRIX 6.5.4
  • SGI IRIX 6.5.3
  • SGI IRIX 6.5.2
  • SGI IRIX 6.5.1
  • SGI IRIX 6.5

Sendmail Consortium Sendmail 5.65
Sendmail Consortium Sendmail 5.61
Sendmail Consortium Sendmail 5.59

Recommendations
Administrators are advised to upgrade to version 8.12.8. Patches are available for 8.12.x, 8.11.x, 8.10.x and 8.9.x versions:

For Sendmail Consortium Sendmail 5.59:

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 5.61:

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 5.65:

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.10:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.10.1:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.10.2:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11.1:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11.2:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11.3:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11.4:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11.5:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.11.6:

Sendmail Consortium Patch sendmail.8.11.6.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.11.6.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.0:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.1:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.2:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.3:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.4:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.5:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.6:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12.7:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12beta10:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12beta12:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12beta16:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12beta5:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.12beta7:

Sendmail Consortium Patch sendmail.8.12.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.8.8:

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.9.0:

Sendmail Consortium Patch sendmail.8.9.3.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.9.3.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.9.1:

Sendmail Consortium Patch sendmail.8.9.3.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.9.3.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.9.2:

Sendmail Consortium Patch sendmail.8.9.3.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.9.3.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

For Sendmail Consortium Sendmail 8.9.3:

Sendmail Consortium Patch sendmail.8.9.3.security.cr.patch
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.9.3.security.cr.patch

Sendmail Consortium Upgrade sendmail.8.12.8.tar.gz
ftp://ftp.sendmail.org/pub/sendmail/sendmail.8.12.8.tar.gz

Credits
Discovered by Mark Dowd of ISS X-Force.


Copyright (c) 2003 by Symantec Corp.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from symsecurity@symantec.com.

Disclaimer
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.

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