SB2017041206 - Two vulnerabilities in Microsoft Active Directory

Description

This security bulletin contains information about 2 vulnerabilities.

1) Brute-force attack (CVE-ID: CVE-2017-0159)

CWE-ID: CWE-307 - Improper Restriction of Excessive Authentication Attempts

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

The vulnerability allows a remote attacker to perform a brute-force attack.

The vulnerability exists when ADFS incorrectly treats requests coming from Extranet clients as Intranet requests. A remote attacker can brute-force account passwords.

Successful exploitation of the vulnerability may allow an attacker to gain unauthorized access to vulnerable system.

2) Denial of service (CVE-ID: CVE-2017-0164)

CWE-ID: CWE-20 - Improper input validation

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

The vulnerability allows a remote authenticated attacker to trigger denial of service.

The vulnerability exists in Active Directory when an authenticated attacker sends malicious search queries. A remote authenticated attacker can perform a denial of service attack against vulnerable system.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0159
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0164