Altium 365 workspace endpoints were configured with an overly permissive Cross-Origin Resource Sharing (CORS) policy that allowed credentialed cross-origin requests from other Altium-controlled subdomains, including forum.live.altium.com. As a result, JavaScript executing on those origins could access authenticated workspace APIs in the context of a logged-in user. When chained with vulnerabilities in those external applications, this misconfiguration enables unauthorized access to workspace data, administrative actions, and bypass of IP allowlisting controls, including in GovCloud environments.
Incorrect CORS configuration in Altium 365 endpoints allowed authenticated cross-origin requests (with cookie/credential transmission) from other Altium subdomains, such as forum.live.altium.com. Malicious JavaScript code executed in the context of these subdomains could invoke protected workspace APIs on behalf of a logged-in user. The attack requires combining this misconfiguration with a separate vulnerability in one of the allowed subdomains, allowing the attacker to construct a scenario in which the victim visits a specially crafted page.
An attacker can gain unauthorized access to workspace data of a logged-in user, perform privileged administrative actions, and bypass access control mechanisms based on IP allowlisting, including in GovCloud environments.
Apply patches available from the vendor according to the references (https://www.altium.com/platform/security-compliance/security-advisories). It is recommended to verify the CORS policy configuration in the Altium 365 environment and monitor workspace API access for unauthorized cross-origin requests.
Altium 365 – workspace endpoints (versions specified in vendor references); the issue also affected GovCloud environments
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H