A issue was discovered in SiteServer CMS 6.9.0. It allows remote attackers to execute arbitrary code because an administrator can add the permitted file extension .aassp, which is converted to .asp because the "as" substring is deleted.

A vulnerability was identified in SiteServer SSCMS up to 7.1.3/7.2.1/7.4.0. This issue affects the function LoginController.Submit of the file src/SSCMS.Web/Controllers/Admin/LoginController.Submit.cs of the component Admin-Login CAPTCHA. Such manipulation of the argument isForceLogoutAndLogin leads to improper restriction of excessive authentication attempts. It is possible to launch the attack remotely. A high complexity level is associated with this attack. The exploitability is assessed as difficult. The name of the patch is df3becb7ebb00a48435418a44fd08a459eb38ace. Applying a patch is advised to resolve this issue.

SiteServer SSCMS through 7.4.0 contains an authorization bypass vulnerability in ChannelsController that allows site-scoped administrators to access other sites' channels by supplying foreign channel IDs. Attackers with Channels permission on one site can read and overwrite another site's channel names, file paths, templates, link URLs, and custom fields, breaking multi-site isolation.

A vulnerability was found in SiteServer SSCMS 7.4.0. Affected by this issue is some unknown functionality of the component Agent Installation Workflow. Performing a manipulation of the argument SecurityKey results in improper access controls. Remote exploitation of the attack is possible. The attack is considered to have high complexity. The exploitation is known to be difficult. The project was informed of the problem early through an issue report but has not responded yet.