How Attackers Exploit Network Vulnerabilities

1. Misconfigurations

Poorly configured security settings create some of the most exploitable vulnerabilities in networks. Attackers take advantage of:

• Overly permissive access controls, allowing unauthorized users to access sensitive systems.
• Default credentials left unchanged, giving attackers easy access to devices and applications.
• Unrestricted cloud storage permissions, exposing critical data to the public internet.

Real-World Example:
In 2019, a misconfigured Amazon S3 bucket led to the exposure of hundreds of millions of Facebook user records, simply because it was set to public instead of private.

2. Weak and Compromised Credentials

Passwords remain one of the weakest links in cybersecurity. Attackers exploit poor credential hygiene through:

• Brute-force attacks – Repeatedly guessing passwords until they succeed.
• Credential stuffing – Using stolen credentials from data breaches to access multiple accounts (since users often reuse passwords).
• Phishing attacks – Tricking users into revealing login details via fake emails and websites.

How Attackers Benefit:
If an attacker gains access to one employee’s credentials, they can escalate privileges, move laterally within the network, and compromise entire systems.

3. Unpatched Software and Zero-Day Exploits

Outdated software contains known security flaws that attackers can easily exploit if patches aren’t applied.

• Unpatched operating systems provide direct access to network infrastructure.
• Vulnerable third-party applications (e.g., VPNs, CMS platforms) serve as entry points.
• Zero-day exploits target newly discovered vulnerabilities before security patches are released.

Notable Attack:
The WannaCry ransomware outbreak in 2017 exploited a vulnerability in Windows SMB (Server Message Block) that had already been patched—but many organizations had failed to apply the update, leading to a global attack affecting over 200,000 systems.

4. Open Ports and Exposed Services

Attackers constantly scan the internet for open and unprotected network ports that can be used to infiltrate systems.

Common attack vectors include:

• Unsecured Remote Desktop Protocol (RDP) – A favorite target for ransomware groups.
• Exposed database ports (e.g., MongoDB, MySQL) – Allow direct access to critical business data.
• Publicly accessible administrative interfaces – Such as unprotected web-based dashboards.

Tactics Used:
Attackers use port scanning tools like Shodan or Nmap to identify open ports and find weak points in an organization’s infrastructure.

5. Man-in-the-Middle (MitM) Attacks

A Man-in-the-Middle (MitM) attack occurs when an attacker secretly intercepts and manipulates communication between two parties.

How attackers execute MitM attacks:

• Intercepting unencrypted data over public Wi-Fi networks.
• DNS spoofing to redirect users to malicious sites.
• Session hijacking to steal authentication tokens and gain access to accounts.

Real-World Impact:
Attackers have used MitM techniques to steal banking credentials, inject malware into legitimate websites, and manipulate financial transactions.

6. Social Engineering and Insider Threats

Not all network vulnerabilities are technical—human error plays a significant role in security breaches. Attackers manipulate employees into:

• Revealing sensitive information over email or phone calls.
• Downloading malware disguised as legitimate files.
• Granting access to systems under false pretenses.

Example:
The 2016 Bangladesh Bank cyber heist was partly enabled by social engineering tactics, leading to a loss of $81 million after attackers tricked employees into authorizing fraudulent transactions.