CVE-2025-4691Network attack vector

Unauthenticated booking disclosure via unchecked request key

Published May 31, 2025 · Updated Apr 8, 2026

Insecure direct object reference in Syntactics eaSYNC Booking 1.3.21 and earlier allows remote attackers to view any booking request. The view_request_details handler uses a user-controlled booking key without validating authorization for the referenced record. No authentication or user interaction is required, and the documented consequence is limited to disclosure of booking details.

CVSS severity5.3
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Insecure direct object reference in Syntactics eaSYNC Booking 1.3.21 and earlier allows remote attackers to view any booking request. The view_request_details handler uses a user-controlled booking key without validating authorization for the referenced record. No authentication or user interaction is required, and the documented consequence is limited to disclosure of booking details.

The record

CVE
CVE-2025-4691
Published
May 31, 2025
Updated
Apr 8, 2026
Vendor
Syntactics, Inc.
Product
eaSYNC Booking – Hotels, Restaurants & Car Rentals
Classifications
CWE-639, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 31, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.3.21

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Syntactics, Inc. · eaSYNC Booking – Hotels, Restaurants & Car Rentalsversion=0 <=1.3.21

Published CVSS scores

5.3WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo