CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:S/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
64.5%
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: 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.
Depending on BookStack version, you could use the 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.
BookStack Beta v0.25.3
BookStack Beta v0.25.4
BookStack Beta v0.25.5
If you have any questions or comments about this advisory:
Vendor | Product | Version | CPE |
---|---|---|---|
ssddanbrown | bookstack | * | cpe:2.3:a:ssddanbrown:bookstack:*:*:*:*:*:*:*:* |
github.com/advisories/GHSA-g9rq-x4fj-f5hx
github.com/BookStackApp/BookStack/releases/tag/v0.25.3
github.com/BookStackApp/BookStack/releases/tag/v0.25.4
github.com/BookStackApp/BookStack/releases/tag/v0.25.5
github.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hx
nvd.nist.gov/vuln/detail/CVE-2020-5256
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:S/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
64.5%