SolarWinds N-central through 2020.1 allows session hijacking and requires user interaction or physical access. The N-Central JSESSIONID cookie attribute is not checked against multiple sources such as sourceip, MFA claim, etc. as long as the victim stays logged in within N-Central. To take advantage of this, cookie could be stolen and the JSESSIONID can be captured. On its own this is not a surprising result; low security tools allow the cookie to roam from machine to machine. The JSESSION cookie can then be used on the attackers’ workstation by browsing to the victim’s NCentral server URL and replacing the JSESSIONID attribute value by the captured value. Expected behavior would be to check this against a second source and enforce at least a reauthentication or multi factor request as N-Central is a highly privileged service.
SolarWinds N-Central version 12.3 GA and lower does not set the JSESSIONID attribute to HTTPOnly. This makes it possible to influence the cookie with javascript. An attacker could send the user to a prepared webpage or by influencing JavaScript to the extract the JESSIONID. This could then be forwarded to the attacker.