Multiple vulnerabilities in Microsoft Windows DNS Server

1) Code Injection

EUVDB-ID: #VU51276

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26893

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the Windows DNS Server. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26893

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Input validation error

EUVDB-ID: #VU51282

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-27063

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input in the Windows DNS Server. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27063

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Input validation error

EUVDB-ID: #VU51281

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26896

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input in the Windows DNS Server. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26896

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Code Injection

EUVDB-ID: #VU51280

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26877

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the Windows DNS Server. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26877

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Code Injection

EUVDB-ID: #VU51279

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26894

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the Windows DNS Server. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26894

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

6) Code Injection

EUVDB-ID: #VU51278

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26895

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the Windows DNS Server. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26895

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

7) Code Injection

EUVDB-ID: #VU51277

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26897

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the Windows DNS Server. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows Server: 2008 R2 - 2019 2004

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26897

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

Risk	High
Patch available	YES
Number of vulnerabilities	7
CVE-ID	CVE-2021-26893 CVE-2021-27063 CVE-2021-26896 CVE-2021-26877 CVE-2021-26894 CVE-2021-26895 CVE-2021-26897
CWE-ID	CWE-94 CWE-20
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Windows Server Operating systems & Components / Operating system
Vendor	Microsoft