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CVE-2024-4936NVD status: Modified

Canto: Improper Control of Filename for Include/Require Statement in PHP Program

CVE-2024-4936 is a critical-severity improper control of filename for include/require statement in PHP program vulnerability in Canto from Flightbycanto, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Canto versions: 3.0.8 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 1.03% chance of exploitation within 30 days, higher than 64% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Canto you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
FlightbycantoCanto3.0.8 and earlierNot stated
Cantocanto3.0.8 and earlierNot 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
NoneNo account or login is needed.
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:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (wordfence.com).

Official description

The Canto plugin for WordPress is vulnerable to Remote File Inclusion in all versions up to, and including, 3.0.8 via the abspath parameter. This makes it possible for unauthenticated attackers to include remote files on the server, resulting in code execution. This required allow_url_include to be enabled on the target site in order to exploit.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Control of Filename for Include/Require Statement in PHP Program

The PHP application receives input from an upstream component, but it does not restrict or incorrectly restricts the input before its usage in require, include, or similar functions.

How developers prevent this class of flaw

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • 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. For example, ID 1 could map to inbox.txt and ID 2 could map to profile.txt. Features such as the ESAPI AccessReferenceMap provide this capability.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Control of Filename for Include/Require Statement in PHP Program vulnerabilities (CWE-98)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Canto

All Canto vulnerabilities

Recent Improper Control of Filename for Include/Require Statement in PHP Program vulnerabilities

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