VPNs provide protection against certain network-based attacks through traffic encryption and IP address masking. Understanding what threats VPNs address and which threats require other security measures helps users assess whether VPNs meet their security requirements. VPNs protect against attacks that occur at the network layer, such as traffic interception, man-in-the-middle attacks, and IP-based targeting. However, VPNs do not protect against application-level threats such as malware, phishing, social engineering, or software vulnerabilities. This page explains how VPNs protect against network-based attacks, specific threat scenarios, and limitations.
Network-Based Attacks That VPNs Protect Against
VPNs provide protection through traffic encryption and IP address masking. These mechanisms protect against network-level attacks where attackers intercept or observe network traffic between users and destinations.
Man-in-the-Middle Attacks
Man-in-the-middle (MITM) attacks occur when attackers position themselves between users and destination servers, intercepting and potentially modifying communications. Attackers can achieve this by compromising network infrastructure, using rogue access points, or leveraging network privileges.
VPN protection: VPN encryption makes intercepted traffic unreadable to attackers. Even if attackers capture VPN-encrypted traffic, they cannot decrypt it without encryption keys. This prevents attackers from reading intercepted data, though it does not prevent all forms of MITM attacks if attackers compromise VPN connections themselves.
Traffic Interception on Public Wi-Fi
Public Wi-Fi networks present security risks because traffic may be unencrypted or attackers may compromise network infrastructure. Common attack vectors include:
- Packet Sniffing: Capturing unencrypted network traffic as it travels across shared networks
- Evil Twin Attacks: Rogue Wi-Fi access points that impersonate legitimate networks to intercept traffic
- Session Hijacking: Capturing authentication tokens, session cookies, or credentials transmitted in unencrypted or weakly encrypted traffic
- SSL Stripping: Attempting to downgrade HTTPS connections to HTTP to enable interception of unencrypted traffic
VPN protection: VPN encryption protects traffic before it leaves user devices, ensuring that intercepted traffic is encrypted even if attackers compromise network infrastructure. This prevents attackers from reading captured traffic, even on compromised or malicious networks. However, VPNs do not protect against attacks that occur before encryption (such as device compromise) or after decryption at VPN servers.
ISP-Level Monitoring and Interference
Internet service providers have access to user network traffic and could potentially:
- Monitor browsing activities and connection patterns
- Inject advertisements or content into web pages
- Modify DNS responses to redirect traffic
- Log and retain user activity data, potentially sharing it with third parties or government agencies
VPN protection: VPN encryption prevents ISPs from observing traffic content. ISPs see only encrypted traffic routed to VPN servers, not destination addresses or content. This prevents ISP-level monitoring, content injection, and DNS manipulation of user traffic. However, ISPs can still observe connection volumes, timing patterns, and VPN server destinations.
IP Address-Based Attacks
IP addresses can be used for various attack purposes:
- Geographic Identification: IP addresses reveal approximate geographic locations, potentially enabling location-based targeting
- DDoS Attacks: Attackers can target specific IP addresses with distributed denial-of-service attacks
- Port Scanning: Attackers can scan IP addresses for open ports and vulnerable services
- Targeted Exploitation: IP addresses can be linked to specific networks or organizations for targeted attacks
VPN protection: VPNs replace user IP addresses with VPN server IP addresses, hiding real IP addresses from destination servers and network observers. This prevents IP-based geographic identification and makes it more difficult for attackers to target user networks directly. VPN server IP addresses are typically hardened against attacks and shared among multiple users, making targeted attacks less effective.
Attacks That VPNs Do Not Protect Against
VPNs operate at the network layer and do not protect against application-level, device-level, or user-level attacks:
Phishing Attacks
Phishing attacks attempt to trick users into voluntarily providing information such as credentials, payment details, or personal data. Phishing attacks typically use social engineering techniques such as fraudulent emails, fake websites, or malicious links.
VPN limitation: VPNs encrypt traffic but cannot prevent users from visiting phishing websites or entering credentials on fake sites. Phishing attacks operate at the application and user level, not the network level. Protection requires user awareness, careful verification of sources, and security tools such as email filters and browser security features.
Malware Infections
Malware refers to malicious software that runs on user devices, including viruses, trojans, ransomware, and spyware. Malware can steal data, compromise systems, or provide backdoors for attackers.
VPN limitation: VPNs encrypt network traffic but do not scan downloads, block malicious software, or prevent malware execution. Malware operates at the device and application level, not the network level. Protection requires antivirus software, careful downloading habits, software updates, and security awareness.
Social Engineering
Social engineering attacks manipulate users into revealing information or taking actions that compromise security. These attacks exploit human psychology rather than technical vulnerabilities.
VPN limitation: VPNs cannot protect against social engineering because these attacks operate through human manipulation rather than network interception. Protection requires security awareness training, healthy skepticism, verification processes, and organizational security policies.
Software Vulnerabilities
Security vulnerabilities in operating systems, applications, or web browsers can be exploited by attackers to gain unauthorized access, execute code, or steal data. Vulnerabilities may exist due to coding errors, configuration issues, or outdated software.
VPN limitation: VPN encryption protects network traffic but does not patch software vulnerabilities or prevent exploitation of vulnerable software. Vulnerabilities must be addressed through software updates, security patches, and secure coding practices. VPNs protect network traffic but cannot prevent attacks that exploit application-level vulnerabilities.
VPN Server Compromise
If VPN servers or VPN provider infrastructure are compromised, attacker access could potentially expose user traffic. VPN providers handle traffic decryption and routing, creating a trust requirement.
Limitation: Users must trust VPN providers to maintain security, not log traffic, and protect against server compromise. VPN provider security practices, jurisdiction, and infrastructure security affect this risk. Users should evaluate VPN providers based on security audits, infrastructure security, and transparency practices.
Browser Tracking and Fingerprinting
Websites can track users through methods that operate independently of network-level protections:
- Cookies stored in browsers that persist across sessions
- Browser fingerprinting that identifies users through browser and device characteristics
- Logged-in accounts that link activities to user identities regardless of IP addresses
VPN limitation: VPNs mask IP addresses but do not prevent cookie-based tracking, browser fingerprinting, or account-based identification. These tracking methods operate at the application and browser level. Protection requires browser privacy tools, privacy-focused browsers, and behavioral practices such as logging out of accounts when not needed.
VPN Protection on Public Wi-Fi Networks
Public Wi-Fi networks present significant security risks because traffic may be unencrypted, network infrastructure may be compromised, or attackers may operate rogue access points. VPNs provide substantial protection in these scenarios.
Without VPN Protection
On public Wi-Fi networks without VPN protection:
- Unencrypted traffic is visible to network observers and attackers
- Login credentials transmitted in unencrypted form can be captured
- Session tokens and cookies can be intercepted and used for unauthorized access
- Users are vulnerable to rogue access points and evil twin attacks
- Network administrators and attackers can monitor all unencrypted traffic
With VPN Protection
VPN protection addresses these risks:
- All traffic is encrypted before transmission, preventing interception and reading
- Captured traffic remains encrypted and unreadable to attackers
- Users are protected even on compromised or malicious networks
- Real IP addresses and specific activities are hidden from network observers
- VPN encryption protects traffic even if network infrastructure is compromised
VPN protection is particularly valuable on public Wi-Fi networks such as coffee shops, hotels, airports, and other shared networks where traffic interception risks are higher.
VPN Security Configuration
Proper VPN configuration enhances protection:
- Automatic Connection: Configure VPNs to connect automatically, especially on untrusted networks, to ensure continuous protection
- Kill Switch: Enable kill switches that block all network traffic if VPN connections fail, preventing IP address exposure during connection drops
- Strong Protocols: Use secure VPN protocols such as WireGuard or OpenVPN rather than outdated or insecure protocols
- Provider Evaluation: Select VPN providers with audited security practices, transparent policies, and strong infrastructure security
- Software Updates: Keep VPN applications updated to ensure security patches and protocol improvements are applied
Comprehensive Security Strategy
VPNs are one component of security protection but should be combined with other security measures:
- VPN: Protects network traffic through encryption and IP masking, addressing network-level threats
- Antivirus Software: Detects and blocks malware infections on devices
- Password Managers: Enable use of strong, unique passwords for all accounts. See password managers for details
- Two-Factor Authentication: Adds additional authentication layers to protect accounts even if passwords are compromised. See what is 2FA for details
- Software Updates: Regularly update operating systems, applications, and browsers to patch security vulnerabilities
- Security Awareness: Educate users about phishing, social engineering, and other user-level threats
- Firewalls: Configure firewalls to block unauthorized network connections and limit exposure
- Browser Security: Use browser privacy tools and security features to protect against tracking and malicious websites
Effective security requires defense in depth, combining multiple layers of protection rather than relying on any single security measure.
Limitations and Considerations
VPN protection has limitations:
- Network Layer Only: VPNs protect network traffic but do not address application-level, device-level, or user-level threats
- Provider Trust: Users must trust VPN providers not to log traffic, compromise security, or misuse data
- Performance Impact: VPN encryption and routing can reduce connection speeds and increase latency
- Connection Reliability: VPN connections can fail, potentially exposing traffic if kill switches are not properly configured
- Not Complete Protection: VPNs protect against network-level attacks but are not sufficient alone for comprehensive security
- Cost: VPNs with adequate security features typically require paid subscriptions
Users should understand these limitations and combine VPNs with other security measures based on their threat models and requirements.