[原文]Integer signedness error in the qmail_put and substdio_put functions in qmail, when running on 64 bit platforms with a large amount of virtual memory, allows remote attackers to cause a denial of service and possibly execute arbitrary code via a large number of SMTP RCPT TO commands.
A remote overflow exists in qmail when running on 64 bit platforms with 4GB of virtual memory or more. The 'substdio_put()' function fails to perform proper bounds checking resulting in an integer overflow. With a specially crafted request, a remote attacker can cause the qmail process to crash resulting in a loss of availability.
Currently, there are no known upgrades, patches, or workarounds available to correct this issue.