CVE-2021-25914Public exploitNetwork attack vector

Service crash via recursive __proto__ object merge

Published Mar 1, 2021 · Updated Apr 30, 2025

Prototype pollution in FireBlink Object Collider 1.0.0 through 1.0.3 allows remote attackers to crash a host application or execute code. The collideObjects loop recursively merges an attacker-controlled proto key into the destination prototype instead of rejecting that key. Exploitation requires a consuming application to pass attacker-controlled objects to the merge API; a crash is direct, while code execution requires a suitable application gadget.

CVSS severity9.8
Critical
EPSS probability3.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in FireBlink Object Collider 1.0.0 through 1.0.3 allows remote attackers to crash a host application or execute code. The collideObjects loop recursively merges an attacker-controlled proto key into the destination prototype instead of rejecting that key. Exploitation requires a consuming application to pass attacker-controlled objects to the merge API; a crash is direct, while code execution requires a suitable application gadget.

The record

CVE
CVE-2021-25914
Published
Mar 1, 2021
Updated
Apr 30, 2025
Vendor
FireBlink
Product
Object Collider
Classifications
CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=1.0.0, 1.0.1, 1.0.2, 1.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FireBlink · Object Colliderversion=1.0.0, 1.0.1, 1.0.2, 1.0.3

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 exploitPublished

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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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