Adobe Acrobat Reader 8.1.2 and earlier, and before 7.1.1, allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a malformed PDF document, as demonstrated by 2008-HI2.pdf.
http://download.oracle.com/sunalerts/1019937.1.html
http://lists.opensuse.org/opensuse-security-announce/2008-11/msg00002.html
http://secunia.com/advisories/32700
http://secunia.com/advisories/32872
http://secunia.com/advisories/35163
https://exchange.xforce.ibmcloud.com/vulnerabilities/42886
https://www.exploit-db.com/exploits/5687
http://www.adobe.com/support/security/bulletins/apsb08-19.html
http://www.adobe.com/support/security/bulletins/apsb09-04.html
http://www.redhat.com/support/errata/RHSA-2008-0974.html
http://www.securitytracker.com/id?1021140
http://www.us-cert.gov/cas/techalerts/TA08-309A.html