Millions of IoT devices and routers could have a mega security flaw
The vulnerability, tracked as CVE-2022-05-02 and discovered by Nozomi Networks, is present in the domain name system (DNS) component of the library uClibc and its uClibc-ng fork from the OpenWRT team. Both uClibc and uClibc-ng are widely used by Netgear, Axis, Linksys and other major vendors as well as in Linux distros designed for embedded applications.
At this time, a fix is currently unavailable from uClibc’s developer which means that devices from more than 200 vendors are currently at risk of DNS poisoning or DNS spoofing that can redirect a potential victim to a malicious website hosted on an attacker controlled server.
Risk of DNS poisoning
Security researchers at Nozomi first came across the vulnerability in uClibc after reviewing traces of DNS requests performed by a connected device at which time they found several peculiarities caused by the library’s internal lookup function. Upon further investigation, the IoT security firm discovered that the transaction IDs of these DNS lookup requests were predictable and therefore DNS poisoning could be possible in certain circumstances.
Nozomi Networks provided further insight in a blog post on what an attacker could accomplish by carrying out DNS poisoning on vulnerable IoT devices and routers, saying:
“A DNS poisoning attack enables subsequent Man-in-the-Middle attacks because the attacker, by poisoning DNS records, is capable of rerouting network communications to a server under their control. The attacker could then steal and/or manipulate information transmitted by users, and perform other attacks against those devices to completely compromise them. The main issue here is how DNS poisoning attacks can force an authenticated response.”