CyberSecBulletin
CVE-2022-25277NVD status: Modified

Core: Unrestricted Upload of File with Dangerous Type

CVE-2022-25277 is a high-severity unrestricted upload of file with dangerous type vulnerability in Core from Drupal, 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. The record lists versions 9.4.3, 9.3.19 as the first without the flaw, so updating Core to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.42% chance of exploitation within 30 days, higher than 73% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Core to 9.4.3 or 9.3.19, whichever matches your release line, or a later version.
  2. Update Drupal to 9.3.19 or 9.4.3, whichever matches your release line, or a later version.
  3. Read the advisory on drupal.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
DrupalCore9.4 up to, but not including, 9.4.3; 9.3 up to, but not including, 9.3.199.4.3, 9.3.19
DrupalDrupal8.0.0 up to, but not including, 9.3.19; 9.4.0 up to, but not including, 9.4.39.3.19, 9.4.3

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
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 systemScoreSeverityScored by
CVSS 3.17.2HighNVD
CVSS 3.17.2HighCISA (ADP)

Official description

Drupal core sanitizes filenames with dangerous extensions upon upload (reference: SA-CORE-2020-012) and strips leading and trailing dots from filenames to prevent uploading server configuration files (reference: SA-CORE-2019-010). However, the protections for these two vulnerabilities previously did not work correctly together. As a result, if the site were configured to allow the upload of files with an htaccess extension, these files' filenames would not be properly sanitized. This could allow bypassing the protections provided by Drupal core's default .htaccess files and possible remote code execution on Apache web servers. This issue is mitigated by the fact that it requires a field administrator to explicitly configure a file field to allow htaccess as an extension (a restricted permission), or a contributed module or custom code that overrides allowed file uploads.

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

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Core

All Core vulnerabilities

Recent Unrestricted Upload of File with Dangerous Type vulnerabilities

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