Is CVE-2020-5256 in the CISA KEV catalog?

No. CVE-2020-5256 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2020-5256?

CVE-2020-5256 has a CVSS v3 base score of 7.9 (HIGH).

What is the EPSS score for CVE-2020-5256?

CVE-2020-5256 has an EPSS score of 1.95% (78th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2020-5256?

Upgrade bookstack to 0.25.3 or later.

CVE & CISA-KEV Catalog

CVE-2020-5256

HIGHEPSS 78th pctl

7.9

CVSS v3

NVD

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.

CWE-95 CWE-434Unrestricted File Upload

How to fix

Remediation Available

bookstackNVD

Affected:< 0.25.3Fixed in:0.25.3CVE-2020-5256derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredLow

User InteractionRequired

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityLow

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

Exploit Intelligence

1.95%probability of exploitation in 30 days

78thpercentile

Elevated risk: more likely to be exploited than 78% of all known CVEs.

References

Third-Party Advisory1

github.com

Release Notes3

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.