CyberSecBulletin
CVE-2023-24373NVD status: Analyzed

Booking calendar, Appointment Booking System: External Control of Assumed-Immutable Web Parameter

CVE-2023-24373 is a critical-severity external control of assumed-immutable web parameter vulnerability in Booking calendar, Appointment Booking System from WpDevArt, 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 Booking calendar, Appointment Booking System versions: 3.2.3 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 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Booking Calendar to 3.2.4 or a later version.
  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
WpDevArtBooking calendar, Appointment Booking System3.2.3 and earlierNot stated
WpdevartBooking Calendarbefore 3.2.43.2.4

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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.13.7LowCNA (patchstack.com)
CVSS 3.19.8CriticalNVD

Official description

External Control of Assumed-Immutable Web Parameter vulnerability in WpDevArt Booking calendar, Appointment Booking System allows Manipulating Hidden Fields.This issue affects Booking calendar, Appointment Booking System: from n/a through 3.2.3.

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

The underlying weakness: External Control of Assumed-Immutable Web Parameter

The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable, such as hidden form fields.

How developers prevent this class of flaw

  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More External Control of Assumed-Immutable Web Parameter vulnerabilities (CWE-472)

Timeline

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

References

Other vulnerabilities in Booking calendar, Appointment Booking System

All Booking calendar, Appointment Booking System vulnerabilities

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