The remote host is missing an update to openssl announced via advisory USN-884-1.
Details follow:
It was discovered that OpenSSL did not correctly free unused memory in certain situations. A remote attacker could trigger this flaw in services that used SSL, causing the service to use all available system memory, leading to a denial of service.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 6.06 LTS: libssl0.9.8 0.9.8a-7ubuntu0.11
Ubuntu 8.04 LTS: libssl0.9.8 0.9.8g-4ubuntu3.9
Ubuntu 8.10: libssl0.9.8 0.9.8g-10.1ubuntu2.6
Ubuntu 9.04: libssl0.9.8 0.9.8g-15ubuntu3.4
Ubuntu 9.10: libssl0.9.8 0.9.8g-16ubuntu3.1
After a standard system upgrade you need to restart any applications using OpenSSL, especially Apache, to effect the necessary changes.