Cisco CyberOps Associate (CBROPS) 200-201Network Intrusion AnalysisHard
A security analyst is investigating an alert from an Intrusion Detection System (IDS) indicating a potential buffer overflow attempt on a web server. The alert details mention unusually long strings of non-alphanumeric characters, including a sequence of 'A's followed by what appears to be shellcode, being sent in a POST request to a CGI script. What specific type of network intrusion is the IDS detecting?
- APath Traversal
- BBuffer Overflow
- CCross-Site Scripting (XSS)
- DSQL Injection
Show answer & explanationAnswer & explanation
Correct answer: B. Buffer Overflow
The mention of unusually long strings, often 'A's, followed by shellcode in input to a CGI script is a classic signature of a buffer overflow attack, where the attacker attempts to overwrite memory and execute arbitrary code.
Why the other options are wrong
- A. Path traversal attempts to access files outside the intended directory structure, not to execute code via buffer manipulation.
- C. XSS injects client-side script into web pages, not shellcode for server execution.
- D. SQL injection manipulates database queries, not server memory via long strings and shellcode.
Buffer Overflow
A buffer overflow occurs when a program attempts to write data to a fixed-size buffer beyond its allocated memory capacity, overwriting adjacent memory locations. Attackers exploit this to inject and execute malicious code (shellcode).
- Exploits memory management vulnerabilities
- Involves sending oversized input to a program
- Often includes padding (e.g., many 'A's) followed by shellcode
- Can lead to arbitrary code execution
Memory trick: Memory attacks are like 'Jumping into the Brain' of a program to take control.