The HTTP dissector in Ethereal 0.10.1 through 0.10.7 allows remote attackers to cause a denial of service (application crash) via a certain packet that causes the dissector to access previously-freed memory.
Ethereal Security Advisory Enpa-sa-00016 - Multiple vulnerabilities in Ethereal versions 0.9.0 to 0.10.7 have been discovered that all result in denial of service outcomes.