OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the MessagesController class of OpenProject has a quote method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip <pre> tags from the message being quoted. The (.|s) part can match a space character in two ways, so an unterminated <pre> tag containing n spaces causes Rubys regex engine to backtrack to try 2n states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openproject | Openproject | * | 11.3.3 (excluding) |
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.