Rubygems.org is the Ruby communitys gem hosting service. A Gem publisher can cause a Remote DoS when publishing a Gem. This is due to how Ruby reads the Manifest of Gem files when using Gem::Specification.from_yaml. from_yaml makes use of SafeYAML.load which allows YAML aliases inside the YAML-based metadata of a gem. YAML aliases allow for Denial of Service attacks with so-called YAML-bombs (comparable to Billion laughs attacks). This was patched. There is is no action required by users. This issue is also tracked as GHSL-2024-001 and was discovered by the GitHub security lab.
The product does not properly control the allocation and maintenance of a limited resource.
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.