# 攻擊與防禦小抄
###### tags: `攻擊與防禦`

- Eavesdropping 竊聽

## CIA

- Confidentiality 機密性
未經授權的使用者不能看到資料。
- Integrity 完整性
確保資料無論是在傳輸或儲存的生命週期中，保有其正確性與一致性。資料不能被竄改。
- Availability 可用性
資料與服務須保持能用，並能滿足使用需求。

## Worm

Four phases:

- Probing
- Exploitation
- Replication
- Payload

## Morris Worm

Spread by:

- SMTP debug mode
- exploiting fingerd
- buffer overflow attack to execute privileged command
- exploiting trust

## Rootkit

Rootkit is a software, used after system compromise to:

- Hide the attacker’s presence
- Provide backdoors for easy reentry

Simple rootkits:
- Modify user programs (ls, ps)
- Detectable by tools like Tripwire

Sophisticated rootkits:
- Modify the kernel itself
- Hard to detect from userland

## Fuzzing

Fuzzing methods:

- Brute-Force Fuzzing
- Most inputs are syntactically invalid
- The inputs are quickly rejected
- Mutational Fuzzing

## ARP Poisoning