CVE-2019-1866Network attack vector

User redirection via unvalidated Host header

Published Apr 13, 2020 · Updated Nov 15, 2024

Improper host-header validation in Cisco Webex Business Suite before 39.1.0 allows man-in-the-middle attackers to redirect users. The application accepts attacker-manipulated Host values from client traffic and uses that untrusted input to redirect Webex Meetings Online users to an arbitrary site. Exploitation requires interception of client network traffic, including wireless traffic, and changes the user's destination.

CVSS severity3.7
Low
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper host-header validation in Cisco Webex Business Suite before 39.1.0 allows man-in-the-middle attackers to redirect users. The application accepts attacker-manipulated Host values from client traffic and uses that untrusted input to redirect Webex Meetings Online users to an arbitrary site. Exploitation requires interception of client network traffic, including wireless traffic, and changes the user's destination.

The record

CVE
CVE-2019-1866
Published
Apr 13, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco Webex Business Suite
Classifications
CWE-284, CWE-345, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 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=unspecified <39.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Webex Business Suiteversion=unspecified <39.1.0

Published CVSS scores

3.7NISTCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
4.3NISTAV:N/AC:M/Au:N/C:N/I:P/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-345Insufficient Verification of Data Authenticity
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

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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