CVE-2020-4828Network attack vector

Unauthenticated web cache poisoning via unvalidated headers

Published Feb 4, 2021 · Updated Sep 16, 2024

Header validation flaws in IBM API Connect 10.0.0.0 through 10.0.1.0 and 2018.4.1.0 through 2018.4.1.13 allow remote attackers to poison web caches. The management server accepts attacker-modified HTTP request headers without sufficient validation, allowing cached responses to be influenced. No authentication or user interaction is required; poisoned entries can cause downstream users to receive attacker-influenced content.

CVSS severity6.5
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Header validation flaws in IBM API Connect 10.0.0.0 through 10.0.1.0 and 2018.4.1.0 through 2018.4.1.13 allow remote attackers to poison web caches. The management server accepts attacker-modified HTTP request headers without sufficient validation, allowing cached responses to be influenced. No authentication or user interaction is required; poisoned entries can cause downstream users to receive attacker-influenced content.

The record

CVE
CVE-2020-4828
Published
Feb 4, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
API Connect
Classifications
CWE-20
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=10.0.0.0
  2. Affected versionversion=10.0.1.0
  3. Affected versionversion=2018.4.1.0
  4. Affected versionversion=2018.4.1.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · API Connectversion=10.0.0.0; version=10.0.1.0; version=2018.4.1.0; version=2018.4.1.13

Published CVSS scores

6.5IBMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
5.7IBMCVSS:3.0/AV:N/C:L/PR:N/UI:N/AC:L/I:L/A:N/S:U/RC:C/RL:O/E:U
6.4NVDAV:N/AC:L/Au:N/C:P/I:P/A:N
6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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 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-20Improper Input Validation

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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