For the second time in two weeks, Macromedia has had to patch bugs in its Flash product line, the company acknowledged Tuesday.

The new vulnerability lies in the Flash Communication Server, which apparently doesn't validate some incoming data, and so can be crashed by sending malicious data from a Flash player.

Danish vulnerability tracker Secunia rated the bug as "Moderately critical" because an exploit would only result in a denial-of-service (DoS) attack; an attacker couldn't inject his own code into a vulnerable computer.

Two other Macromedia server packages, Breeze Communication Server and Breeze Live Server, labor under the same cloud, while yet another, Contribute Publishing Server, has an unexpectedly weak password mechanism that could be exploited by local users -- those within the network -- to gain unauthorized access.

All three vulnerabilities have been patched, with updated editions available from Macromedia's support site. The update to Flash Communication Server, for instance, can be found here.

The week before last, Macromedia released fixes for its popular Flash media player to stymie attackers who might grab control of a computer by tricking the user into running a specially-crafted file.