DNS cache poisoning is an attack that places false DNS records in a resolver’s cache. The resolver may then send users or devices to an attacker-controlled or compromised destination when they look up a legitimate domain.
What DNS cache poisoning means
DNS resolvers look up domain names and cache answers so they can reuse DNS data instead of making a fresh lookup every time. Cache poisoning occurs when a resolver accepts false DNS data and stores it. Later clients that rely on that resolver can receive the incorrect answer.
As an Amazon Associate I earn from qualifying purchases.
Some guidance uses “DNS spoofing” for this kind of cache corruption. “DNS hijacking” is broader and can describe other ways of subverting DNS resolution. Usage varies, so the key distinction is whether false data has been stored in a resolver’s cache.
Free tools Windows power users keep installed
One-click scans. No signup required.
How does DNS cache poisoning work?
A caching resolver sends a query and checks incoming responses against the query and DNS protocol requirements. In a forged-response attack, an adversary tries to make a false reply arrive before the legitimate one and match the outstanding query. If accepted, the answer can be cached and reused. MITRE CAPEC-142 describes crafted replies that match a transaction ID and arrive before the authorized answer.
#1 Best Overall
- DUAL-BAND WIFI 6 ROUTER: Wi-Fi 6(802.11ax) technology achieves faster speeds, greater capacity and reduced network congestion compared to the previous gen. All WiFi routers require a separate modem. Dual-Band WiFi routers do not support the 6 GHz band.
- AX1800: Enjoy smoother and more stable streaming, gaming, downloading with 1.8 Gbps total bandwidth (up to 1200 Mbps on 5 GHz and up to 574 Mbps on 2.4 GHz). Performance varies by conditions, distance to devices, and obstacles such as walls.
- CONNECT MORE DEVICES: Wi-Fi 6 technology communicates more data to more devices simultaneously using revolutionary OFDMA technology
- EXTENSIVE COVERAGE: Achieve the strong, reliable WiFi coverage with Archer AX1800 as it focuses signal strength to your devices far away using Beamforming technology, 4 high-gain antennas and an advanced front-end module (FEM) chipset
- OUR CYBERSECURITY COMMITMENT: TP-Link is a signatory of the U.S. Cybersecurity and Infrastructure Security Agency’s (CISA) Secure-by-Design pledge. This device is designed, built, and maintained, with advanced security as a core requirement.
A historical weakness made this easier: DNS used a 16-bit Query ID to associate replies with queries. ISC’s advisory for CVE-2008-1447 documents the 2008 vulnerability and its spoofing risk. The enduring lesson is to keep resolver software supported and patched; the advisory’s old version lists and patch instructions are not current deployment guidance.
What can a poisoned DNS cache do?
A resolver with a false record can return the wrong address for a real domain. A user or system relying on that answer may connect to a malicious or compromised host, creating opportunities for phishing or other traffic diversion. If an upstream resolver supplies inaccurate data, downstream resolvers can also receive and cache it.
Rank #2
- New-Gen WiFi Standard – WiFi 6(802.11ax) standard supporting MU-MIMO and OFDMA technology for better efficiency and throughput.Antenna : External antenna x 4. Processor : Dual-core (4 VPE). Power Supply : AC Input : 110V~240V(50~60Hz), DC Output : 12 V with max. 1.5A current.
- Ultra-fast WiFi Speed – RT-AX1800S supports 1024-QAM for dramatically faster wireless connections
- Increase Capacity and Efficiency – Supporting not only MU-MIMO but also OFDMA technique to efficiently allocate channels, communicate with multiple devices simultaneously
- 5 Gigabit ports – One Gigabit WAN port and four Gigabit LAN ports, 10X faster than 100–Base T Ethernet.
- Commercial-grade Security Anywhere – Protect your home network with AiProtection Classic, powered by Trend Micro. And when away from home, ASUS Instant Guard gives you a one-click secure VPN.
Redirection does not by itself prove that an attacker can defeat HTTPS or steal credentials. The outcome depends on the destination and the application’s other security checks; poisoning establishes a risk of redirection, not inevitable compromise.
How to reduce the risk of DNS cache poisoning
Validate DNSSEC where the data is signed
Enable DNSSEC validation on recursive resolvers. DNSSEC lets a validating resolver authenticate DNS data and authenticated denial of existence. It can reject data that fails validation when the relevant zone is signed and the trust chain is valid. It does not protect unsigned data or resolve every kind of compromise. See RFC 3833 for DNS threat-analysis background.
Rank #3
- Tri-Band WiFi 6E Router - Up to 5400 Mbps WiFi for faster browsing, streaming, gaming and downloading, all at the same time(6 GHz: 2402 Mbps;5 GHz: 2402 Mbps;2.4 GHz: 574 Mbps)
- WiFi 6E Unleashed – The 6 GHz band brings more bandwidth, faster speeds, and near-zero latency; Enables more responsive gaming and video chatting
- Connect More Devices—True Tri-Band and OFDMA technology increase capacity by 4 times to enable simultaneous transmission to more devices
- Unique Design, More RAM, Better Processing - A unique housing design provides optimal heat dissipation, combined with a 1.0 GHz dual-core CPU and 512 MB High-Speed Memory, the AXE75 is designed for long-term reliability and performance.
- EasyMesh-compatible - Extend network range even more by adding EasyMesh-compatible routers, extenders, or wireless powerline adapters for a seamless, whole-home connection. Eliminate dead zones, drops, and lag as you move across your home.
Maintain resolver software and query unpredictability
Use supported resolver software and apply the current security guidance from its vendor. Standards-based measures that add unpredictability to queries make forged answers harder to match; RFC 5452 sets out resilience measures against forged DNS responses. ISC’s historical advisory also describes varying source ports to increase outgoing-query variability.
Consider DNS Cookies as a complementary defense
DNS Cookies help authenticate DNS transactions and can deter some forged replies sent by off-path attackers. RFC 7873 says, “With the use of DNS Cookies, a resolver can generally reject such forged replies.” The standard characterizes the protection as significant but limited: Cookie benefits depend on client and server support, and Cookies complement rather than replace DNSSEC data validation. Read RFC 7873.
Quick Recap
Best Value
- 【Five Gigabit Ports】1 Gigabit WAN Port plus 2 Gigabit WAN/LAN Ports plus 2 Gigabit LAN Port. Up to 3 WAN ports optimize bandwidth usage through one device.
- 【One USB WAN Port】Mobile broadband via 4G/3G modem is supported for WAN backup by connecting to the USB port. For complete list of compatible 4G/3G modems, please visit TP-Link website.
- 【Abundant Security Features】Advanced firewall policies, DoS defense, IP/MAC/URL filtering, speed test and more security functions protect your network and data.
- 【Highly Secure VPN】Supports up to 20× LAN-to-LAN IPsec, 16× OpenVPN, 16× L2TP, and 16× PPTP VPN connections.
- Security - SPI Firewall, VPN Pass through, FTP/H.323/PPTP/SIP/IPsec ALG, DoS Defence, Ping of Death and Local Management. Standards and Protocols IEEE 802.3, 802.3u, 802.3ab, IEEE 802.3x, IEEE 802.1q
Rank #4
- Dual-band Wi-Fi with 5 GHz speeds up to 867 Mbps and 2.4 GHz speeds up to 300 Mbps, delivering 1200 Mbps of total bandwidth¹. Dual-band routers do not support 6 GHz. Performance varies by conditions, distance to devices, and obstacles such as walls.
- Covers up to 1,000 sq. ft. with four external antennas for stable wireless connections and optimal coverage.
- Supports IGMP Proxy/Snooping, Bridge and Tag VLAN to optimize IPTV streaming
- Access Point Mode - Supports AP Mode to transform your wired connection into wireless network, an ideal wireless router for home
- Advanced Security with WPA3 - The latest Wi-Fi security protocol, WPA3, brings new capabilities to improve cybersecurity in personal networks
How to investigate a suspicious DNS answer
- Preserve the evidence. Record the resolver’s answer and retain relevant logs before changing resolver state.
- Compare the answer. Check the suspicious result against authoritative DNS data for the name, taking account of the zone’s DNSSEC status.
- Check validation. Review whether DNSSEC validation succeeded or failed for the answer.
- Interpret the signal cautiously. A mismatch or validation failure warrants investigation but is not proof of an attack; misconfigured domains can produce similar symptoms. Incorrect data may also remain in caches until they are flushed.
- Follow product-specific recovery guidance. Use the resolver vendor’s current instructions for any cache-clearing or recovery action; there is no universal safe cache-flushing procedure for every resolver.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
