Risk | High |
Patch available | YES |
Number of vulnerabilities | 1 |
CVE-ID | CVE-2021-20837 |
CWE-ID | CWE-78 |
Exploitation vector | Network |
Public exploit | Public exploit code for vulnerability #1 is available. |
Vulnerable software |
Movable Type Web applications / CMS Movable Type Advanced Web applications / CMS Movable Type Premium Web applications / CMS Movable Type Premium Advanced Web applications / CMS |
Vendor | Six Apart Ltd |
Security Bulletin
This security bulletin contains one high risk vulnerability.
EUVDB-ID: #VU57555
Risk: High
CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]
CVE-ID: CVE-2021-20837
CWE-ID:
CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation in Movable Type XMLRPC API. A remote unauthenticated attacker can send a specially crafted message and execute arbitrary OS commands 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 versionsMovable Type: r.5002 - 6.8.2
Movable Type Advanced: r.5002 - 6.8.2
Movable Type Premium: 1.46
Movable Type Premium Advanced: 1.46
CPE2.3https://jvn.jp/en/jp/JVN41119755/index.html
https://movabletype.org/news/2021/10/mt-782-683-released.html
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. However, proof of concept for this vulnerability is available.