Multiple vulnerabilities in Microsoft Exchange Server
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2021-31209 CVE-2021-31207 CVE-2021-31198 CVE-2021-31195 |
| CWE-ID | CWE-354 CWE-254 CWE-94 |
| Exploitation vector | Network |
| Public exploit |
Vulnerability #2 is being exploited in the wild. Public exploit code for vulnerability #4 is available. |
| Vulnerable software Subscribe |
Microsoft Exchange Server Server applications / Mail servers |
| Vendor | Microsoft |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
Updated: 01.06.2021
Updated vulnerability #1.
1) Improper validation of integrity check value
EUVDB-ID: #VU53082
Risk: Medium
CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-31209
CWE-ID:
CWE-354 - Improper Validation of Integrity Check Value
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to bypass integrity checks.
Install updates from vendor's website.
Vulnerable software versionsMicrosoft Exchange Server: 2013 Cumulative Update 23 15.00.1497.002 - 2019 Cumulative Update 9 15.02.0858.005
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31209
http://www.zerodayinitiative.com/advisories/ZDI-21-615/
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Security features bypass
EUVDB-ID: #VU53085
Risk: Low
CVSSv3.1: 5.8 [CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-31207
CWE-ID:
CWE-254 - Security Features
Exploit availability: Yes
DescriptionThe vulnerability allows a remote user to bypass authentication process.
The vulnerability exists due to security feature bypass issue in Microsoft Exchange Server. A remote administrator can gain full access to target system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMicrosoft Exchange Server: 2013 Cumulative Update 23 15.00.1497.002 - 2019 Cumulative Update 9 15.02.0858.005
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Code Injection
EUVDB-ID: #VU53084
Risk: High
CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-31198
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation in Microsoft Exchange Server. A remote attacker can execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMicrosoft Exchange Server: 2013 Cumulative Update 23 15.00.1497.002 - 2019 Cumulative Update 9 15.02.0858.005
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31198
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) Code Injection
EUVDB-ID: #VU53083
Risk: High
CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-31195
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation in Microsoft Exchange Server. A remote attacker can execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMicrosoft Exchange Server: 2013 Cumulative Update 23 15.00.1497.002 - 2019 Cumulative Update 9 15.02.0858.005
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31195
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
