The remote host is missing an update to apache2 announced via advisory DSA 1834-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201834-1

A denial of service flaw was found in the Apache mod_proxy module when it was used as a reverse proxy. A remote attacker could use this flaw to force a proxy process to consume large amounts of CPU time. This issue did not affect Debian 4.0 etch. (CVE-2009-1890) A denial of service flaw was found in the Apache mod_deflate module. This module continued to compress large files until compression was complete, even if the network connection that requested the content was closed before compression completed. This would cause mod_deflate to consume large amounts of CPU if mod_deflate was enabled for a large file. A similar flaw related to HEAD requests for compressed content was also fixed. (CVE-2009-1891) For the stable distribution (lenny), these problems have been fixed in version 2.2.9-10+lenny4. The oldstable distribution (etch), these problems have been fixed in version 2.2.3-4+etch9. For the testing distribution (squeeze) and the unstable distribution (sid), these problems will be fixed in version 2.2.11-7. This advisory also provides updated apache2-mpm-itk packages which have been recompiled against the new apache2 packages. Updated packages for the s390 and mipsel architectures are not included yet. They will be released as soon as they become available.