cms: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2023-32679 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, < 4.4.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.85% chance of exploitation within 30 days, higher than 79% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Craft CMS to 4.4.6 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, < 4.4.6 | Not stated |
| Craft CMS | Craft CMS | 4.0.0 up to, but not including, 4.4.6 | 4.4.6 |
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 CMS is an open source content management system. In affected versions of Craft CMS an unrestricted file extension may lead to Remote Code Execution. If the name parameter value is not empty string('') in the View.php's doesTemplateExist() -> resolveTemplate() -> _resolveTemplateInternal() -> _resolveTemplate() function, it returns directly without extension verification, so that arbitrary extension files are rendered as twig templates. When attacker with admin privileges on a DEV or an improperly configured STG or PROD environment, they can exploit this vulnerability to remote code execution. Code execution may grant the attacker access to the host operating system. This issue has been addressed in version 4.4.6. Users are advised to upgrade. There are no known workarounds for this vulnerability.
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
Other vulnerabilities in cms
- 9.8 Critical severity
- 8.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.2 High severity
- 8.8 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 10.0 Critical severity
- 7.3 High severity
- 7.3 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
Spotted an error? Tell us.