CVE-2020-4640

User impersonation via cached URL-fragment data

Published Feb 4, 2021 · Updated Sep 16, 2024

Information exposure in IBM API Connect 10.0.0.0 through 10.0.1.0 and 2018.4.1.0 through 2018.4.1.13 enables user impersonation. Affected management-server configurations place sensitive data in URL fragment identifiers, allowing intermediary proxies, CDNs, and logging platforms to cache it. Exploitation requires adjacent access, low privileges, and user interaction; the exposed material supports impersonation but not service interruption.

CVSS severity3.4
Low
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information exposure in IBM API Connect 10.0.0.0 through 10.0.1.0 and 2018.4.1.0 through 2018.4.1.13 enables user impersonation. Affected management-server configurations place sensitive data in URL fragment identifiers, allowing intermediary proxies, CDNs, and logging platforms to cache it. Exploitation requires adjacent access, low privileges, and user interaction; the exposed material supports impersonation but not service interruption.

The record

CVE
CVE-2020-4640
Published
Feb 4, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
API Connect
Classifications
T1550
Attack vector
adjacent
Privileges
authenticated

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 vectoradjacent
Required privilegesauthenticated

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

3.4IBMCVSS:3.0/AV:A/AC:H/PR:L/UI:R/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)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1550Use Alternate Authentication Material

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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