Is CVE-2019-3977 actively exploited?

No active exploitation of CVE-2019-3977 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2019-3977 be exploited remotely?

Yes. CVE-2019-3977 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2019-3977?

CVE-2019-3977 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2019-3977

HIGH

CVE-2019-3977

CWE-494Published: October 29, 2019· Updated: Jun 17, 2026

7.5

CVSS v3.1

Official Description

RouterOS 6.45.6 Stable, RouterOS 6.44.5 Long-term, and below insufficiently validate where upgrade packages are download from when using the autoupgrade feature. Therefore, a remote attacker can trick the router into "upgrading" to an older version of RouterOS and possibly reseting all the system's usernames and passwords.

NVD Source

Technical Analysis

CVE-2019-3977 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.