text_combined: bmordiconnicholsoncom ben mord original message crispin cowan mailtocrispinwirexcom sent wednesday september 04 2002 730 pm ben mord cc webappsec securityfocuscom secprog securityfocus subject use base image delta image automated recovery attacks ben mord wrote original message crispin cowan mailtocrispinwirexcom sent wednesday september 04 2002 546 pm ben mord cc webappsec securityfocuscom secprog securityfocus subject use base image delta image automated recovery attacks ben mord wrote proposed solution first two problems mention less ambitious idea never commit instead simply revert base state reboot ah case use something considerably less powerful vmware need machine configured boot cdrom use ram disk scratch space numerous linux distros available let boot stateless functional system cdrom ram expensive directory structures many systems eg windows sufficiently organized standardized make combination bootable cds ram drives practical even fortunate enough using linux another fhscompliant nix still cant fit lot cd unusual today gigabytes static multimedia content web server particular problem alleviated somewhat using dvds temporary solution best become outdated quickly data requirements grow hard drives become cheaper obviously cant partitions accrue important state eg partition stores database table data want state persist need mountable writable partition protect need kind access control management decide writable partition blah blah blah know security problem starts look like conventional servers right would consolidate state longterm significance couple partitions would put static application code changeable partitions fortunately large clientserver application physical architectures anyhow two fundamentally different kinds state two different sets administrative security raid backup requirements people also tend anyhow layered logical architectures popular gui one end business logic middle persistence services logical architecture maps naturally physical architecture static web server static application server database server static changeable partitions use word static versus changeable instead writeable versus unwritable unchangeable partitions might written temporary swap space knows windows internally point market hardware raid device split designated partitions permanent base image partition temporary delta image partition simple solid security measures prevent unauthorized remote modification base images configured clear delta image server rebooted vendor wished implement could market mechanism help frustrate broad classes attack rely permanent modification system application files via buffer overflows platform middleware bugs etc prevention unauthorized modification application data course would addressed particular product many techniques defend application data techniques assume system compromised lower level product could help would think features would relatively easy hardware raid vendor implement im guessing course knowledge hardware raid works internally anyone knows product id love hear ben thu 5 sep 2002 114240 0400 use base image delta image automated recovery