It was discovered that dpkg-deb does not properly sanitize directory permissions when extracting a control member into a temporary directory, which is documented as being a safe operation even on untrusted data. This may result in leaving temporary files behind on cleanup. Given automated and repeated execution of dpkg-deb commands on adversarial .deb packages or with well compressible files, placed inside a directory with permissions not allowing removal by a non-root user, this can end up in a DoS scenario due to causing disk quota exhaustion or disk full conditions.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Dpkg | Debian | * | 1.22.21 (excluding) |
| Dpkg | Ubuntu | devel | * |
| Dpkg | Ubuntu | jammy | * |
| Dpkg | Ubuntu | noble | * |
| Dpkg | Ubuntu | oracular | * |
| Dpkg | Ubuntu | plucky | * |
| Dpkg | Ubuntu | questing | * |
| Dpkg | Ubuntu | upstream | * |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.