CVE-2020-5256

描述

### Impact A user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely. They would then have the permissions of the PHP process. This most impacts scenarios where non-trusted users are given permission to upload images in any area of the application. ### Patches The issue was addressed in a series of patches: v0.25.3, v0.25.4 and v0.25.5. Users should upgrade to at least v0.25.5 to avoid this patch but ideally the latest BookStack version as previous versions are un-supported. ### Workarounds Depending on BookStack version, you could use the [local_secure](https://www.bookstackapp.com/docs/admin/upload-config/#local-secure) image storage option, or use s3 or a similar compatible service. Preventing direct execution of any `php` files, apart from the `public/index.php` file, though web-server configuration would also prevent this. ### References [BookStack Beta v0.25.3](https://github.com/BookStackApp/BookStack/releases/tag/v0.25.3) [BookStack Beta v0.25.4](https://github.com/BookStackApp/BookStack/releases/tag/v0.25.4) [BookStack Beta v0.25.5](https://github.com/BookStackApp/BookStack/releases/tag/v0.25.5) ### For more information If you have any questions or comments about this advisory: * Open an issue in [the BookStack GitHub repository](BookStackApp/BookStack/issues). * Ask on the [BookStack Discord chat](https://discord.gg/ztkBqR2). * Follow the [BookStack Security advise](https://github.com/BookStackApp/BookStack#-security) to contact someone privately.

如何修補 CVE-2020-5256

要修補 CVE-2020-5256,請將受影響套件升級到下列已修補版本。

• —升級至 0.25.5 或更新版本

CVE-2020-5256 正在被利用嗎?

低 — EPSS 為 2.0%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• from 0, < 0.25.5