Source: cret@cert.org
Amped Wireless R10000 devices with firmware 2.5.2.11 use an improper algorithm for selecting the ID value in the header of a DNS query, which makes it easier for remote attackers to spoof responses by predicting this value.
Amped Wireless R10000 devices running firmware 2.5.2.11 are vulnerable to DNS spoofing due to a flawed method of generating DNS query IDs. This allows attackers to intercept and manipulate DNS traffic, potentially redirecting users to malicious websites or enabling other network attacks, leading to data breaches and system compromise.
Step 1: Target Identification: The attacker identifies the target Amped Wireless R10000 device and its IP address.
Step 2: DNS Query Observation: The attacker monitors DNS queries originating from the target device, looking for the domain names being requested.
Step 3: ID Prediction: The attacker analyzes the DNS query ID generation method used by the vulnerable device. This could involve observing multiple queries to identify a pattern or using publicly available information about the firmware.
Step 4: Malicious Response Crafting: The attacker crafts a malicious DNS response that spoofs the legitimate DNS server's response. This response contains the correct DNS query ID (predicted by the attacker) and points the requested domain name to an attacker-controlled IP address.
Step 5: Response Injection: The attacker sends the malicious DNS response to the target device, attempting to beat the legitimate DNS response from the authoritative server.
Step 6: Cache Poisoning: If the attacker's response arrives first, the target device caches the malicious DNS record. Subsequent requests for the same domain name will be resolved to the attacker's IP address.
Step 7: Redirection and Exploitation: The target device now directs traffic for the spoofed domain to the attacker's server, enabling various attacks, such as phishing, malware distribution, or man-in-the-middle attacks.
The vulnerability lies in the use of an insecure random number generator (RNG) or a predictable algorithm for generating the 16-bit ID field in DNS query headers. This ID is used to match requests with responses. If the ID is easily predictable, an attacker can craft a malicious DNS response with the correct ID and send it before the legitimate response from the authoritative DNS server. This allows the attacker to effectively poison the DNS cache of the vulnerable device, causing it to resolve domain names to attacker-controlled IP addresses. The root cause is likely a simple algorithm like incrementing a counter or using a weak pseudo-random number generator, making it easy to guess the ID value.
While no specific APT groups are directly linked to this CVE, the nature of DNS spoofing makes it a valuable tool for various attackers. This vulnerability could be leveraged by financially motivated actors, nation-state actors, or script kiddies. Not listed on CISA KEV.
Monitor DNS traffic for unusual patterns, such as rapid changes in DNS resolution for specific domains.
Analyze DNS query logs for suspicious activity, such as multiple DNS responses with the same query ID.
Implement network intrusion detection systems (IDS) with rules to detect DNS spoofing attempts.
Monitor for unexpected connections to attacker-controlled IP addresses.
Examine DNS server logs for inconsistencies or signs of cache poisoning.
Upgrade to the latest firmware version for the Amped Wireless R10000 device. If no updated firmware is available, consider replacing the device.
Implement DNSSEC (DNS Security Extensions) to cryptographically verify DNS responses and prevent spoofing. This requires support from both the DNS server and the client.
Configure the router to use a reputable DNS server that supports DNSSEC validation.
Segment the network to limit the impact of a successful DNS spoofing attack.
Regularly review and audit network configurations for security vulnerabilities.
Implement strong network monitoring to detect and respond to suspicious activity.