Auth bypass in Mikrotik Routeros

CVE-2019-3978

RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below allow remote unauthenticated attackers to trigger DNS queries via port 8291. The queries are sent from the router to a server of the attacker's choice. The DNS responses are cached by the router, potentially resulting in cache poisoning

Vulnerability class: Broken Authentication

EPSS: 0.103 (95.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

  • Mikrotik Routeros
  • N/a Mikrotik Routeros — versions RouterOS 6.45.6 Stable and below. RouterOS 6.44.5 Long-term and below.

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-3978?
CVE-2019-3978 is a high-severity vulnerability in Mikrotik Routeros, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2019-10-29.
How severe is CVE-2019-3978?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2019-3978 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.