When logging out, the session ID was not invalidated. This is not a problem while the user is logged out, but as soon as the user logs back in the old session ID would be valid again; which means that anyone that gained access to the old session cookie would be able to act as the logged in user. This is not a major concern for the majority of cases, since it requires a malicious party gaining access to the session cookie in the first place, but nevertheless has been fixed.
Issue has been patched in Build 472 (v1.0.472) and v1.1.2.
Apply https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024 to your installation manually if unable to upgrade to Build 472 or v1.1.2.
If you have any questions or comments about this advisory:
{
"cwe_ids": [
"CWE-613"
],
"github_reviewed": true,
"github_reviewed_at": "2021-02-10T02:30:45Z",
"nvd_published_at": "2021-02-05T14:15:00Z",
"severity": "CRITICAL"
}