Contact Form 7: Unrestricted Upload of File with Dangerous Type
CVE-2023-6449 is a high-severity unrestricted upload of file with dangerous type vulnerability in Contact Form 7 from Rocklobsterinc, 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 Contact Form 7 versions: 5.8.3 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.75% chance of exploitation within 30 days, higher than 78% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Contact Form 7 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Rocklobsterinc | Contact Form 7 | 5.8.3 and earlier | 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
- 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 | 6.6 | Medium | CNA (wordfence.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
The Contact Form 7 plugin for WordPress is vulnerable to arbitrary file uploads due to insufficient file type validation in the 'validate' function and insufficient blocklisting on the 'wpcf7_antiscript_file_name' function in versions up to, and including, 5.8.3. This makes it possible for authenticated attackers with editor-level capabilities or above to upload arbitrary files on the affected site's server, but due to the htaccess configuration, remote code cannot be executed in most cases. By default, the file will be deleted from the server immediately. However, in some cases, other plugins may make it possible for the file to live on the server longer. This can make remote code execution possible when combined with another vulnerability, such as local file inclusion.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unrestricted Upload of File with Dangerous Type
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
How developers prevent this class of flaw
- Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.
More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)
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
Third-party and government advisories
Other references
Recent Unrestricted Upload of File with Dangerous Type vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.2 High severity
- 7.2 High severity
- 8.8 High severity
- 8.8 High severity
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