CVE-2021-37331Public exploitNetwork attack vector

Identity-document disclosure via user-controlled object reference

Published Oct 4, 2021 · Updated Aug 4, 2024

Insecure direct object reference in Booking Core 2.0 allows remote attackers to read other users' identity documents through a changed URL. The Verifications document-view endpoint accepts an object reference from the URL and returns the referenced ID Card or Trade License without enforcing ownership. Reachability requires access to a document-view URL and a valid alternate reference; the reported consequence is disclosure of another user's uploaded document.

CVSS severity5.3
Medium
EPSS probability0.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure direct object reference in Booking Core 2.0 allows remote attackers to read other users' identity documents through a changed URL. The Verifications document-view endpoint accepts an object reference from the URL and returns the referenced ID Card or Trade License without enforcing ownership. Reachability requires access to a document-view URL and a valid alternate reference; the reported consequence is disclosure of another user's uploaded document.

The record

CVE
CVE-2021-37331
Published
Oct 4, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-639
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
5.3NIST NVDCVSS: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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key

Public exploit references

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

Technologies

Your stack

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Your stack

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