Input validation error in MikroTik RouterOS - CVE-2019-3979
Published: October 30, 2019
Vulnerability identifier: #VU22427
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2019-3979
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: MikroTik
Affected software:
MikroTik RouterOS
MikroTik RouterOS
Detailed vulnerability description
The vulnerability allows a remote attacker to poison DNS cache.
The vulnerability exists due to insufficient validation of DNS responses, returned by the DNS server. A remote attacker can force the router to make a DNS request to a malicious DNS server and add DNS "A" records for arbitrary domain name to the router's DNS cache. As a result, a remote attacker can force the RouterOS to return incorrect information for DNS requests for arbitrary domain name and redirect all user's traffic to a malicious server.
How to mitigate CVE-2019-3979
Install updates from vendor's website.