xwiki-platform: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-37913 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in xwiki-platform from XWiki, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected xwiki-platform versions: >= 3.5-milestone-1, < 14.10.8; >= 15.0-rc-1, < 15.3-rc-1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.36% chance of exploitation within 30 days, higher than 72% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Xwiki to 14.10.8 or 15.3, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| XWiki | xwiki-platform | >= 3.5-milestone-1, < 14.10.8; >= 15.0-rc-1, < 15.3-rc-1 | Not stated |
| XWiki | Xwiki | 3.5 up to, but not including, 14.10.8; 15.0 up to, but not including, 15.3 | 14.10.8, 15.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.9 | Critical | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Starting in version 3.5-milestone-1 and prior to versions 14.10.8 and 15.3-rc-1, triggering the office converter with a specially crafted file name allows writing the attachment's content to an attacker-controlled location on the server as long as the Java process has write access to that location. In particular in the combination with attachment moving, a feature introduced in XWiki 14.0, this is easy to reproduce but it also possible to reproduce in versions as old as XWiki 3.5 by uploading the attachment through the REST API which doesn't remove `/` or `\` from the filename. As the mime type of the attachment doesn't matter for the exploitation, this could e.g., be used to replace the `jar`-file of an extension which would allow executing arbitrary Java code and thus impact the confidentiality, integrity and availability of the XWiki installation. This vulnerability has been patched in XWiki 14.10.8 and 15.3RC1. There are no known workarounds apart from disabling the office converter.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
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.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other vulnerabilities in xwiki-platform
- 7.1 High severity
- 8.2 High severity
- 7.5 High severity
- 9.3 Critical severity
- 8.6 High severity
- 7.5 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 7.1 High severity
- 7.2 High severity
- 7.5 High severity
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