Overview
Attackers manipulate DNS responses to redirect users to malicious servers or websites, often mimicking legitimate ones. DNS spoofing, also known as DNS cache poisoning, occurs when attackers manipulate the DNS (Domain Name System) resolution process, redirecting users to malicious websites that appear legitimate. When a mobile app or browser requests a domain name (e.g., www.example.com), a compromised DNS server may return an incorrect IP address, leading the user to a fake site designed to steal information, distribute malware, or conduct phishing attacks.
Risk factors
DNS spoofing attacks can arise from:
- Attackers targeting poorly secured or misconfigured DNS servers to inject malicious DNS entries
- Public networks that are often vulnerable to DNS spoofing attacks due to weaker security controls
- Failing to implement DNS Security Extensions (DNSSEC) leaves DNS queries vulnerable to tampering
- HTTP traffic that is more vulnerable to DNS spoofing than HTTPS, as it lacks encryption and verification mechanisms
Consequences
If an attacker successfully exploits DNS spoofing, the following could happen:
- Phishing attacks: Users may be redirected to fake websites that look like legitimate ones, leading to the theft of login credentials or personal information.
- Malware installation: Attackers may use DNS spoofing to redirect users to sites that distribute malware, such as ransomware or spyware.
- Data interception: Attackers can use fake websites to intercept sensitive information, such as payment details or account credentials.
- Reputation damage: Users may lose trust in the app if they are consistently redirected to malicious websites due to DNS spoofing.
Solution and best practices
To mitigate the risks associated with DNS spoofing attacks, organizations should implement the following security measures:
- Implement DNSSEC: Use DNS Security Extensions (DNSSEC) to verify the integrity of DNS responses and protect against DNS spoofing attacks.
- Use HTTPS: Ensure that all communication between the app and server is encrypted with HTTPS, making it harder for attackers to redirect users to malicious sites.
- Use trusted DNS providers: Advise users to use DNS services from reputable DNS providers with strong security practices, such as Cloudflare (1.1.1.1), Google (8.8.8.8), or Quad9 (9.9.9.9), which support DNSSEC and DNS-over-HTTPS (DoH).
- App shielding: App shielding can help detect and block attempts to manipulate DNS responses, adding an extra layer of protection against DNS spoofing.