CVE-2019-3978
CWE-306Published: October 29, 2019· Updated: Jun 17, 2026
Official Description
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
Technical Analysis
CVE-2019-3978 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.5.
A proof-of-concept (PoC) exploit exists for CVE-2019-3978. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-306)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2019-3978 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts