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Remote Code Execution through Zip Slip in Xibo CMS

High
alexharrington published GHSA-jj27-x85q-crqv May 30, 2023

Package

composer xibosignage/xibo-cms (Composer)

Affected versions

>= 1.8.0, < 2.3.17
>= 3.0.0, < 3.3.5

Patched versions

2.3.17
3.3.5

Description

Impact

A path traversal vulnerability exists in the Xibo CMS whereby a specially crafted zip file can be uploaded to the CMS via the layout import function by an authenticated user which would allow creation of files outside of the CMS library directory as the webserver user. This can be used to upload a PHP webshell inside the web root directory and achieve remote code execution as the webserver user.

Patches

Users should upgrade to version 2.3.17 or 3.3.5 which fix this issue. Customers who host their CMS with Xibo Signage have already received an upgrade or patch to resolve this issue regardless of the CMS version that they are running.

Workarounds

Patches are available for earlier versions of Xibo CMS that are out of security support:
1.8.13
2.0.6
2.1.3

We do however advise upgrading to a supported version.

References

Xibo Signage Security Advisory
Claroty Team82 Disclosure

Credit

Thanks to Noam Moshe of Claroty Research who discovered this issue.

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVE ID

CVE-2023-33177

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Learn more on MITRE.