Bunkum up to 4.2.0 release of resource

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Bunkum up to 4.2.0. Affected is an unknown function. Performing a manipulation results in release of resource. This vulnerability is identified as CVE-2023-45814. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Bunkum up to 4.2.0. This affects an unknown functionality. The manipulation with an unknown input leads to a release of resource vulnerability. CWE is classifying the issue as CWE-772. The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. This is going to have an impact on confidentiality. The summary by CVE is:

Bunkum is an open-source protocol-agnostic request server for custom game servers. First, a little bit of background. So, in the beginning, Bunkum's `AuthenticationService` only supported injecting `IUser`s. However, as Refresh and SoundShapesServer implemented permissions systems support for injecting `IToken`s into endpoints was added. All was well until 4.0. Bunkum 4.0 then changed to enforce relations between `IToken`s and `IUser`s. This wasn't implemented in a very good way in the `AuthenticationService`, and ended up breaking caching in such a way that cached tokens would persist after the lifetime of the request - since we tried to cache both tokens and users. From that point until now, from what I understand, Bunkum was attempting to use that cached token at the start of the next request once cached. Naturally, when that token expired, downstream projects like Refresh would remove the object from Realm - and cause the object in the cache to be in a detached state, causing an exception from invalid use of `IToken.User`. So in other words, a use-after-free since Realm can't manage the lifetime of the cached token. Security-wise, the scope is fairly limited, can only be pulled off on a couple endpoints given a few conditions, and you can't guarantee which token you're going to get. Also, the token *would* get invalidated properly if the endpoint had either a `IToken` usage or a `IUser` usage. The fix is to just wipe the token cache after the request was handled, which is now in `4.2.1`. Users are advised to upgrade. There are no known workarounds for this vulnerability.

The weakness was released 10/19/2023 as GHSA-jrf2-h5j6-3rrq. The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2023-45814 since 10/13/2023. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 4.2.1 eliminates this vulnerability. Applying the patch 6e109464ed9255f558182f001f475a378405ff76 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Name

• Bunkum

Version

• 4.0
• 4.1
• 4.2.0

License

• open-source

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CPE 2.2info

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