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CVE-2020-5256

HIGHCVSS 8.8/10EPSS 1.95%

Last modified

CVE-2020-5256 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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. EPSS estimates a 1.95% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
1.95%

77.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
BookstackappBookstack< 0.25.3

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-5256?
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.
How severe is CVE-2020-5256?
CVE-2020-5256 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.95% probability of exploitation in the next 30 days.
How do I fix CVE-2020-5256?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-5256?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST