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CVE-2020-5256

7.9 · HIGH

BookStack before version 0.25.5 has a vulnerability where a user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely.

Published Mar 9, 2020CWE-95EPSS 1.97%

Overview

CVE-2020-5256 is a high-severity vulnerability. It was published on March 9, 2020 and has a CVSS 3.1 base score of 7.9 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.9, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.

Technical description

BookStack before version 0.25.5 has a vulnerability where 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. The issue was addressed in a series of patches in versions 0.25.3, 0.25.4 and 0.25.5. Users should upgrade to at least v0.25.5 to avoid this vulnerability.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

GitHubgithub.com/BookStackApp/BookStack/releases/tag/v0.25.3GitHubgithub.com/BookStackApp/BookStack/releases/tag/v0.25.4GitHubgithub.com/BookStackApp/BookStack/releases/tag/v0.25.5GitHubgithub.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hxGitHubgithub.com/BookStackApp/BookStack/releases/tag/v0.25.3GitHubgithub.com/BookStackApp/BookStack/releases/tag/v0.25.4GitHubgithub.com/BookStackApp/BookStack/releases/tag/v0.25.5GitHubgithub.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hx

How CyberStrike helps

Frequently asked questions

What is CVE-2020-5256?

CVE-2020-5256 is a high-severity vulnerability. It was published on March 9, 2020 and has a CVSS 3.1 base score of 7.9 (HIGH).

How severe is CVE-2020-5256?

This vulnerability has a CVSS 3.1 base score of 7.9, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2020-5256?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2020-5256?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2020-5256 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

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