# GHSA-4vr3-9v7h-5f8v: Low severity vulnerability that affects Gw2Sharp > Cached authenticated responses may leak data between users sharing a cache instance, requiring specific client configuration to exploit. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 18 Jun 2019 ## What is GHSA-4vr3-9v7h-5f8v? GHSA-4vr3-9v7h-5f8v is a vulnerability in Gw2Sharp, published on 18 Jun 2019. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description ## Leaking cached authenticated requests ### Impact If you've been using one `MemoryCacheMethod` object in multiple instances of `Gw2WebApiClient` and are requesting authenticated endpoints with different access tokens, then you are likely to run into this bug. When using an instance of `MemoryCacheMethod` and using it with multiple instances of `Gw2WebApiClient`, there's a possibility that cached authenticated responses are leaking to another request to the same endpoint, but with a different Guild Wars 2 access token. The latter request wouldn't start however, and would return the first cached response immediately. This means that the second response (or later responses) may contain the same data as the first response, therefore leaking data from another authenticated endpoint. The occurence of this is limited however. The Guild Wars 2 API doesn't use the `Expires` header on most (if not all) authenticated endpoints. This header is checked when caching responses. If this header isn't available, the response isn't cached at all. You should still update to at least version 0.3.1 in order to be certain that it won't happen. ### Patches This bug has been fixed in version 0.3.1. When using an authenticated endpoint, it will prepend the SHA-1 hash of the access token to the cache id. ### Workarounds For version 0.3.0 and lower, you can use one separate instance of `MemoryCacheMethod` per `Gw2WebApiClient` if you need to use it. ### For more information If you have any questions or comments about this advisory, you can open an issue in [the Gw2Sharp repository](https://github.com/Archomeda/Gw2Sharp) or contact me on [Discord](https://discord.gg/hNcpDT3). ## Which versions are affected by GHSA-4vr3-9v7h-5f8v? 2 open source packages ship an affected version, including Gw2Sharp. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `Gw2Sharp` | NuGet | All versions | 0.3.1 | | `Gw2Sharp` | NuGet | All versions | 0.3.1 | ## How do I fix GHSA-4vr3-9v7h-5f8v? Upgrade Gw2Sharp to 0.3.1 or later. ## Is GHSA-4vr3-9v7h-5f8v being exploited? There is no known exploitation of GHSA-4vr3-9v7h-5f8v in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for GHSA-4vr3-9v7h-5f8v and fix it if it is affected. What it is: GHSA-4vr3-9v7h-5f8v is a vulnerability in Gw2Sharp, published on 18 Jun 2019. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of GHSA-4vr3-9v7h-5f8v in the wild and no public exploit code. Affected packages and fixed versions: - Gw2Sharp (NuGet): affected all versions; fixed in 0.3.1 - Gw2Sharp (NuGet): affected all versions; fixed in 0.3.1 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/GHSA-4vr3-9v7h-5f8v/ (Markdown: https://insights.sbomify.com/GHSA-4vr3-9v7h-5f8v/index.md) ``` ## Sources - OSV: https://osv.dev/vulnerability/GHSA-4vr3-9v7h-5f8v --- From sbomify Insights: https://insights.sbomify.com/GHSA-4vr3-9v7h-5f8v/ Summaries are generated and may contain mistakes; the official description above is the record.