What’s Vulnerable › Vulnerabilities

CVE-2021-42654

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-05-24 · updated 2026-06-17
• Weakness: CWE-434

Description

SiteServer CMS < V5.1 is affected by an unrestricted upload of a file with dangerous type (getshell), which could be used to execute arbitrary code.

Affected products

• SiteServer CMS: before 5.1 — fixed in 5.1

How to fix

Upgrade to a fixed version: SiteServer CMS 5.1. Check the vendor advisory for mitigations.

References

• https://github.com/siteserver/cms
• https://github.com/siteserver/cms/issues/3236
• https://github.com/siteserver/cms/releases/download/siteserver-dev-v5.0.92/siteserver_install.zip
• https://github.com/siteserver/cms
• https://github.com/siteserver/cms/issues/3236
• https://github.com/siteserver/cms/releases/download/siteserver-dev-v5.0.92/siteserver_install.zip

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