winter: Incomplete List of Disallowed Inputs
CVE-2024-54149 is a high-severity incomplete list of disallowed inputs vulnerability in winter from Wintercms, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, but only if a user takes part, for example by opening a link or file. Affected winter versions: >= 1.2.0, < 1.2.7; >= 1.1.0, < 1.1.11; < 1.0.476. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.42% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of winter you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Wintercms | winter | >= 1.2.0, < 1.2.7; >= 1.1.0, < 1.1.11; < 1.0.476 | Not stated |
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
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:R/S:C/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
Winter is a free, open-source content management system (CMS) based on the Laravel PHP framework. Winter CMS prior to versions 1.2.7, 1.1.11, and 1.0.476 allow users with access to the CMS templates sections that modify Twig files to bypass the sandbox placed on Twig files and modify resources such as theme customisation values or modify, or remove, templates in the theme even if not provided direct access via the permissions. As all objects passed through to Twig are references to the live objects, it is also possible to also manipulate model data if models are passed directly to Twig, including changing attributes or even removing records entirely. In most cases, this is unwanted behavior and potentially dangerous. To actively exploit this security issue, an attacker would need access to the Backend with a user account with any of the following permissions: `cms.manage_layouts`; `cms.manage_pages`; or `cms.manage_partials`. The Winter CMS maintainers strongly recommend that these permissions only be reserved to trusted administrators and developers in general. The maintainers of Winter CMS have significantly increased the scope of the sandbox, effectively making all models and datasources read-only in Twig, in versions 1.2.7, 1.1.11, and 1.0.476. Thse who cannot upgrade may apply commit fb88e6fabde3b3278ce1844e581c87dcf7daee22 to their Winter CMS installation manually to resolve the issue. In the rare event that a Winter user was relying on being able to write to models/datasources within their Twig templates, they should instead use or create components to make changes to their models.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incomplete List of Disallowed Inputs
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.
How developers prevent this class of flaw
- Do not rely exclusively on detecting disallowed inputs. There are too many variants to encode a character, especially when different environments are used, so there is a high likelihood of missing some variants. Only use detection of disallowed inputs as a mechanism for detecting suspicious activity. Ensure that you are using other protection mechanisms that only identify good input - such as lists of allowed inputs - and ensure that you are properly encoding your outputs.
More Incomplete List of Disallowed Inputs vulnerabilities (CWE-184)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in winter
- 8.3 High severity
- 7.1 High severity
- 8.1 High severity
- 8.1 High severity
- 8.4 High severity
- 9.9 Critical severity
Recent Incomplete List of Disallowed Inputs vulnerabilities
- 8.8 High severity
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