CyberSecBulletin
CVE-2022-2594NVD status: Modified

Advanced Custom Fields: Unrestricted Upload of File with Dangerous Type

Published Updated By the CyberSecBulletin desk

CVE-2022-2594 is a high-severity unrestricted upload of file with dangerous type vulnerability in Advanced Custom Fields from TODO, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions 5.0*, 5.12.3 as the first without the flaw, so updating Advanced Custom Fields to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.61% chance of exploitation within 30 days, higher than 76% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Advanced Custom Fields to 5.0* or 5.12.3, whichever matches your release line, or a later version.
  2. Update Advanced Custom Fields Pro to 5.0* or 5.12.3, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. 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

VendorProductAffected versionsFixed in
TODOAdvanced Custom Fields5.0 up to, but not including, 5.0*; 5.12.3 up to, but not including, 5.12.35.0*, 5.12.3
TODOAdvanced Custom Fields Pro5.0 up to, but not including, 5.0*; 5.12.3 up to, but not including, 5.12.35.0*, 5.12.3

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
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

The Advanced Custom Fields WordPress plugin before 5.12.3, Advanced Custom Fields Pro WordPress plugin before 5.12.3 allows unauthenticated users to upload files allowed in a default WP configuration (so PHP is not possible) if there is a frontend form available. This vulnerability was introduced in the 5.0 rewrite and did not exist prior to that release.

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. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Recent Unrestricted Upload of File with Dangerous Type vulnerabilities

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