cms: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2023-40035 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in cms from Craft CMS, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected cms versions: >= 4.0.0-RC1, < 4.4.15; >= 3.0.0, < 3.8.15. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.32% chance of exploitation within 30 days, higher than 84% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Craft CMS to 3.8.15 or 4.4.15, 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 |
|---|---|---|---|
| Craft CMS | cms | >= 4.0.0-RC1, < 4.4.15; >= 3.0.0, < 3.8.15 | Not stated |
| Craft CMS | Craft CMS | 3.0.0 up to, but not including, 3.8.15; 4.0.0 up to, but not including, 4.4.15; 4.0.0 | 3.8.15, 4.4.15 |
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
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.2 | High | CNA (github.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
Craft is a CMS for creating custom digital experiences on the web and beyond. Bypassing the validatePath function can lead to potential remote code execution. This vulnerability can lead to malicious control of vulnerable systems and data exfiltrations. Although the vulnerability is exploitable only in the authenticated users, configuration with ALLOW_ADMIN_CHANGES=true, there is still a potential security threat (Remote Code Execution). This issue has been patched in version 4.4.15 and version 3.8.15.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
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 cms
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Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
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