What’s Vulnerable › Vulnerabilities

CVE-2021-20837

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 88.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-10-26 · updated 2026-06-17
• Weakness: CWE-78

Description

Movable Type 7 r.5002 and earlier (Movable Type 7 Series), Movable Type 6.8.2 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.5002 and earlier (Movable Type Advanced 7 Series), Movable Type Advanced 6.8.2 and earlier (Movable Type Advanced 6 Series), Movable Type Premium 1.46 and earlier, and Movable Type Premium Advanced 1.46 and earlier allow remote attackers to execute arbitrary OS commands via unspecified vectors. Note that all versions of Movable Type 4.0 or later including unsupported (End-of-Life, EOL) versions are also affected by this vulnerability.

Affected products

• Six Apart Ltd. Movable Type: through 1.46; from 4.0 through 6.3.11; from 6.5.0 through 6.8.2; from 7.0 through 7.8.1

References

• http://packetstormsecurity.com/files/164705/Movable-Type-7-r.5002-XMLRPC-API-Remote-Command-Injection.html
• http://packetstormsecurity.com/files/164818/Movable-Type-7-r.5002-XMLRPC-API-Remote-Command-Injection.html
• https://jvn.jp/en/jp/JVN41119755/index.html
• https://movabletype.org/news/2021/10/mt-782-683-released.html
• http://packetstormsecurity.com/files/164705/Movable-Type-7-r.5002-XMLRPC-API-Remote-Command-Injection.html
• http://packetstormsecurity.com/files/164818/Movable-Type-7-r.5002-XMLRPC-API-Remote-Command-Injection.html
• https://jvn.jp/en/jp/JVN41119755/index.html
• https://movabletype.org/news/2021/10/mt-782-683-released.html

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