SB2019103004 - Multiple vulnerabilities in Mokrotik RouterOS

Description

This security bulletin contains information about 4 vulnerabilities.

1) Path traversal (CVE-ID: CVE-2019-3976)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the filenames of the packages. A remote attacker can trick the victim into installing an updated with a specially crafted name and enable developer shell.

2) Insufficient verification of data authenticity (CVE-ID: CVE-2019-3977)

CWE-ID: CWE-345 - Insufficient Verification of Data Authenticity

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to software does not validate origin of the upgrade packages when using autoupgrade feature. A remote attacker can trick the victim into downloading and installing an old version of RouterOS and reset passwords of all system users.

3) Incorrect permission assignment for critical resource (CVE-ID: CVE-2019-3978)

CWE-ID: CWE-732 - Incorrect Permission Assignment for Critical Resource

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/U:Green

The vulnerability allows a remote attacker to perform DNS cache poisoning attacks.

The vulnerability exists due to RouterOS allows a remote attacker to initiate DNS queries via port 8291/TCP. A remote attacker can force the router to send DNS requests to an attacker-contorted server and poison router's DNS cache.

4) Input validation error (CVE-ID: CVE-2019-3979)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 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

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.

Remediation

Install update from vendor's website.

References

• https://mikrotik.com/download/changelogs#6.45.7
• https://www.tenable.com/security/research/tra-2019-46
• https://github.com/tenable/routeros/tree/master/option_npk/