December 2005

ID: 01134
Ref: 1066/2005
Date: 23 December 2005:10:01:38
Version: 1

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Title: Two iDEFENSE Security Advisories: 1. iDEFENSE Security Advisory: ESB-2005.1009 - McAfee Security Center MCINSCTL.DLL ActiveX Control File Overwrite. 2. Linux Kernel Socket Buffer Memory Exhaustion DoS Vulnerability
Abstract:
Vendors affected: iDEFENSE
Operating systems affected: iDEFENSE
Applications affected: iDEFENSE

---

Title
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Two iDEFENSE Security Advisories:

1. iDEFENSE Security Advisory: ESB-2005.1009 - McAfee Security Center MCINSCTL.DLL
ActiveX Control File Overwrite.

2. Linux Kernel Socket Buffer Memory Exhaustion DoS Vulnerability

Detail
======

1. Remote exploitation of an access control vulnerability in McAfee
Security Center allows attackers to create or overwrite arbitrary
files.

2. Local exploitation of a memory exhaustion vulnerability in Linux Kernel
versions 2.4 and 2.6 can allow attackers to cause a denial of service
condition.



1.


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===========================================================================


ESB-2005.1009 -- [Win]
McAfee Security Center MCINSCTL.DLL ActiveX Control File Overwrite
23 December 2005

===========================================================================



Product: McAfee VirusScan
Publisher: iDEFENSE
Operating System: Windows
Impact: Create Arbitrary Files
Overwrite Arbitrary Files
Access: Remote/Unauthenticated
CVE Names: CVE-2005-3657

Original Bulletin:
http://www.idefense.com/intelligence/vulnerabilities/display.php?id=358

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McAfee Security Center MCINSCTL.DLL ActiveX Control File Overwrite

iDefense Security Advisory 12.20.05
http://www.idefense.com/intelligence/vulnerabilities/display.php?id=358
December 20, 2005

I. BACKGROUND

McAfee VirusScan is an anti-virus software. More information is
available from the vendor website:

http://www.mcafee.com/myapps/

II. DESCRIPTION

Remote exploitation of an access control vulnerability in McAfee
Security Center allows attackers to create or overwrite arbitrary
files.

The vulnerability specifically exists due to a registered ActiveX
control failing to restrict which domains may load the control for
execution. MCINSCTL.DLL as included with McAfee Security Center exports
an object for logging called MCINSTALL.McLog. The McLog object is
designed to allow Security Center to log to a file through the StartLog
and AddLog methods. McAfee fails to restrict the ActiveX control from
being loaded in arbitrary domains. As such, attackers can create a
specially crafted web page utilizing the McLog object to create
arbitrary files. This attack can lead to arbitrary code execution by a
remote attacker.

III. ANALYSIS

Successful exploitation of this vulnerability allows attackers to
create or append to arbitrary files. An attacker can write to a startup
folder to execute arbitrary code during the next reboot or logon
session. A user will not be required to authorize the object
instantiation since the object is within a signed ActiveX control. A
typical exploitation scenario would require an attacker to convince a
targeted user to visit a malicious website.

This vulnerability hints at a new class of vulnerabilities that occur
due to developers not using the IObjectSafetySiteLock() API to restrict
domains that can load a particular ActiveX control. Vendors who
distributed third-party ActiveX controls should be sure to use the
IObjectSafetySiteLock() API in their applications.

IV. DETECTION

McAfee Security Center is a component that is distributed with various
McAfee products. The following products have been confirmed to contain
a vulnerable mcinsctl.dll component in their distribution:

# McAfee VirusScan (mcinsctl.dll 4.0.0.83)

V. WORKAROUND

iDefense is unaware of any effective workarounds at this time.

VI. VENDOR RESPONSE

"McAfee previously released updates to SecurityCenter that resolve this
issue. All active McAfee SecurityCenter users, by default, should have
automatically received the update, and will now have the fix for this
vulnerability already installed on their computers.

To manually check for updates, users can right-click the McAfee system
tray icon (white M on red background) and select 'Updates'. In the
resulting dialogue box, they should click 'Check Now' to check the
server for updates. The user will be walked through the update process
or be notified that all software is up to date. If a user has not yet
registered, a registration web page or the registration wizard will
pop-up, guiding the user through the update process.

McAfee's key priority is the security of our customers. In the event
that a vulnerability is found within any of McAfee's software, we have a
strong process in place to work closely with the relevant security
research group to ensure the rapid and effective development of a fix
and communication plan."

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2005-3657 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

11/15/2005 Initial vendor notification
11/16/2005 Initial vendor response
12/20/2005 Coordinated public disclosure

IX. CREDIT

iDefense credits Peter Vreugdenhil with the discovery of this
vulnerability.

Get paid for vulnerability research
http://www.iDefense.com/poi/teams/vcp.jsp

Free tools, research and upcoming events
http://labs.iDefense.com

X. LEGAL NOTICES

Copyright © 2005 iDefense, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDefense. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice@iDefense.com for permission.

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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2.


Linux Kernel Socket Buffer Memory Exhaustion DoS Vulnerability

iDefense Security Advisory 12.22.05
http://www.idefense.com/intelligence/vulnerabilities/display.php?id=362
December 22, 2005

I. BACKGROUND

Linux is a clone of the operating system Unix, written from scratch by
Linus Torvalds with assistance from a loosely-knit team of hackers
across the Net. It aims towards POSIX and Single UNIX Specification
compliance.

More information is available from the vendor website:

http://www.kernel.org

II. DESCRIPTION

Local exploitation of a memory exhaustion vulnerability in Linux Kernel
versions 2.4 and 2.6 can allow attackers to cause a denial of service
condition.

The vulnerability specifically exists due to a lack of resource checking
during the buffering of data for transfer over a pair of sockets. An
attacker can create a situation that, depending on the amount of
available system resources, can cause the kernel to panic due to memory
resource exhaustion. The attack is conducted by opening up a number of
connected file descriptors or socketpairs and creating the largest
possible kernel buffer for the data transfer between the two sockets. By
causing the process to enter a zombie state or closing the file
descriptor while keeping a reference open, the data is kept in the
kernel until the transfer can complete. If done repeatedly, system
memory resources can be exhausted from the kernel.

III. ANALYSIS

Successful exploitation requires an attacker to have local access to an
affected Linux system and can result in complete system denial of
service. The system may not reboot after successful exploitation,
requiring human interaction to be restored to a working state. Depending
on available resources, systems with large amounts of physical memory
may not be affected.

IV. DETECTION

iDefense has confirmed that Linux 2.4.22 and Linux 2.6.12 are
vulnerable.

V. WORKAROUND

An effective workaround is not available for this vulnerability.

VI. VENDOR RESPONSE

The maintainer acknowledges that this issue is a design limitation in
the Linux kernel. The following advice has been offered for creating a
patch. It should be noted that this patch has not been fully tested.

The patch requires three steps:

1) Add a "struct user *" reference to the "struct file" file structure.

2) Whenever creating a new "struct file" add the following code:

struct user *user = current->user;

if (atomic_read(&user->files) > MAX_FILES_FOR_THIS_USER)
return -EMFILE;

file->user = user;
if(user) {
atomic_inc(&user->count);
atomic_inc(&user->files);
}

3) Whenever a "struct file" is released apply the following code:

struct user *user = file->user;

if (user) {
atomic_dec(&user->files);
free_uid(user);
}

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-3660 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

11/17/2005 Initial vendor notification - Linux vendors
11/19/2005 Initial vendor responses
12/22/2005 Public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

Get paid for vulnerability research
http://www.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com

X. LEGAL NOTICES

Copyright © 2005 iDefense, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDefense. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice@idefense.com for permission.

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.