CVE-2021-2453Network attack vector

Service interruption via undisclosed filter flaw

Published Jul 20, 2021 · Updated Sep 25, 2024

Denial of service in Oracle Outside In Technology 8.5.5 allows remote attackers to hang or repeatedly crash applications via HTTP. Oracle identifies the locus as Outside In Filters but has not published the malformed input, parser operation, or code path responsible. Network reachability exists only when consuming software passes HTTP-supplied data into the SDK; successful exploitation interrupts that application's service.

CVSS severity7.5
High
EPSS probability1.06%
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 Oracle Outside In Technology 8.5.5 allows remote attackers to hang or repeatedly crash applications via HTTP. Oracle identifies the locus as Outside In Filters but has not published the malformed input, parser operation, or code path responsible. Network reachability exists only when consuming software passes HTTP-supplied data into the SDK; successful exploitation interrupts that application's service.

The record

CVE
CVE-2021-2453
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

7.5Oracle CorporationCVSS: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.

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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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