An overflow exists in the Pegasus mail client. The MUA fails to process long headers over 259 characters in the To: or From: fields resulting in a buffer overflow. With a specially crafted request, an attacker can cause a crash or possibly execute code resulting in a loss of integrity and/or availability.
Denial of Service,
Loss of Availability
Upgrade to version Pegasus Mail 4.02 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.