ubuntu-image 1.0 before 2017-07-07, when invoked as non-root, creates files in the resulting image with the uid of the invoking user. When the resulting image is booted, a local attacker with the same uid as the image creator has unintended access to cloud-init and snapd directories.
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
Name | Vendor | Start Version | End Version |
---|---|---|---|
Ubuntu-image | Canonical | 1.0-2017-07-06 (including) | 1.0-2017-07-06 (including) |
Ubuntu-image | Ubuntu | devel | * |
Ubuntu-image | Ubuntu | esm-infra/xenial | * |
Ubuntu-image | Ubuntu | upstream | * |
Ubuntu-image | Ubuntu | xenial | * |
Ubuntu-image | Ubuntu | yakkety | * |
Ubuntu-image | Ubuntu | zesty | * |
Such a scenario is commonly observed when:
In the generic exploit of session fixation vulnerabilities, an attacker creates a new session on a web application and records the associated session identifier. The attacker then causes the victim to associate, and possibly authenticate, against the server using that session identifier, giving the attacker access to the user’s account through the active session.