"Adobe Reader is free software that lets you view and print Adobe Portable Document Format (PDF) files on a variety of devices and operating systems."
Remote exploitation of a buffer overflow in Adobe Reader's mailListIsPdf() function that is available for UNIX systems could allow for execution of arbitrary code.
The vulnerability exists in the mailListIsPdf() function which 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.
Impact
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.
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
A patch is listed below: --- 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"
Vendor Status:
The vendor has released a fixed version of Acrobat Reader. Users are encouraged to upgrade to the newer 5.0.10 version.
