CVE-2021-2420Network attack vector

Unauthenticated service hang or repeatable crash

Published Jul 20, 2021 · Updated Sep 25, 2024

Denial of service in Outside In Filters in Oracle Outside In Technology 8.5.5 allows remote attackers to hang or crash the SDK via HTTP. Oracle has not published the malformed input, parser routine, or incorrect operation that triggers the failure. Exposure requires a consuming application to pass network-received data directly into the SDK; successful attacks affect availability only.

CVSS severity7.5
High
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Outside In Filters in Oracle Outside In Technology 8.5.5 allows remote attackers to hang or crash the SDK via HTTP. Oracle has not published the malformed input, parser routine, or incorrect operation that triggers the failure. Exposure requires a consuming application to pass network-received data directly into the SDK; successful attacks affect availability only.

The record

CVE
CVE-2021-2420
Published
Jul 20, 2021
Updated
Sep 25, 2024
Vendor
Oracle Corporation
Product
Oracle Outside In Technology
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 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?

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

  1. Affected versionversion=8.5.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle Corporation · Oracle Outside In Technologyversion=8.5.5

Published CVSS scores

5.0NISTAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5Oracle CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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