iDEFENSE Security Advisory 12.14.04 - Adobe Acrobat Reader 5.0.9 mailListIsPdf() Buffer Overflow Vulnerability

2004-12-15T00:00:00
ID SECURITYVULNS:DOC:7330
Type securityvulns
Reporter Securityvulns
Modified 2004-12-15T00:00:00

Description

Adobe Acrobat Reader 5.0.9 mailListIsPdf() Buffer Overflow Vulnerability

iDEFENSE Security Advisory 12.14.04 www.idefense.com/application/poi/display?id=161&type=vulnerabilities December 14, 2004

I. BACKGROUND

Adobe Acrobat Reader is a program for viewing Portable Document Format (PDF) documents. More information is available at the following site:

http://www.adobe.com/products/acrobat/readermain.html

II. DESCRIPTION

Remote exploitation of a buffer overflow in version 5.09 of Adobe Acrobat Reader for Unix could allow for execution of arbitrary code.

The vulnerability specifically exists in a the function mailListIsPdf().

This function checks if the input file is an email message containing a PDF. It unsafely copies user supplied data using strcat into a fixed sized buffer.

III. ANALYSIS

Successful exploitation allows an attacker to execute arbitrary code under the privileges of the local user. Remote exploitation is possible by sending a specially crafted e-mail and attaching either the maliciously crafted PDF document or a link to it.

IV. DETECTION

iDEFENSE has confirmed the existence of this vulnerability in Adobe Acrobat Reader version 5.0.9 for Unix. Previous versions of Adobe Acrobat Reader 5 for Unix are suspected also to be vulnerable.

V. WORKAROUND

User awareness is the best defense against this class of attack. Users should be aware of the existence of such attacks and proceed with caution when following links from suspicious and/or unsolicited e-mail.

Additionally, you may wish to apply the following unofficial patch from iDEFENSE Labs to the acroread shell script. The acroread shell script calls the appropriate binary for the platform. The patch adds a check that ensures that files passed as arguments to acroread are in fact PDF documents. This patch will not protect against files opened from within the Acrobat Reader GUI.

The bin/ directory of the application contains an 'acroread' shell script while the Reader/ directory contains a binary with the same name. The command 'file acroread', when executed in the same directory as the shell script, should return the line:

acroread: a /bin/sh script text executable

This result indicates the existence of the appropriate file that the patch below can be applied to.

acroread.patch:

--- acroread.orig 2004-10-13 17:25:57.000000000 -0400 +++ acroread 2004-10-13 17:55:43.000000000 -0400 @@ -309,6 +309,16 @@ fi

if [ -f "$ACRO_EXEC_CMD" ] ; then + for CHECK in ${1+"$@"}; + do + [ -f "$CHECK" ] && { + file "$CHECK" | grep "PDF document" || \ + { + echo "$CHECK" exists, but is not a PDF document. + exit 1; + } + } + done exec "$ACRO_EXEC_CMD" ${1+"$@"} else echo "ERROR: Cannot find $ACRO_EXEC_CMD"

VI. VENDOR RESPONSE

This vulnerability is fixed in Adobe Acrobat Reader 5.0.10 for Unix. Further details of the vulnerability are available in the following knowledgebase article:

http://www.adobe.com/support/techdocs/331153.html

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2004-1152 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

10/14/2004 Initial vendor notification 10/15/2004 Initial vendor response 12/14/2004 Coordinated public disclosure

IX. CREDIT

This vulnerability was discovered by Greg MacManus, iDEFENSE Labs.

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

X. LEGAL NOTICES

Copyright (c) 2004 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.