CVE-2019-3978 — RouterOS versions 6

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 result

01What is this vulnerability?

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

02Affected products

Vendor	Product	Versions
n	a / MikroTik RouterOS	RouterOS 6.45.6 Stable and below. RouterOS 6.44.5 Long-term and below.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-10-28T21:32:57.000Z
• Last modified: 2024-08-04T19:26:27.327Z

09References

• www.tenable.com — https://www.tenable.com/security/research/tra-2019-46
• packetstormsecurity.com — http://packetstormsecurity.com/files/155036/MikroTik-RouterOS-6.45.6-DNS-Cache-P…