CVE-2020-11877Network attack vector

Encrypted-data exposure via fixed AES-CBC IV

Published Apr 17, 2020 · Updated Aug 4, 2024

Cryptographic weakness in airhost.exe in Zoom Client for Meetings 4.6.11 exposes encrypted data to remote attackers through a fixed AES-CBC IV. The executable supplies the constant 3423423432325249 as the initialization vector for AES-256-CBC instead of generating a fresh unpredictable value. Zoom states that the affected code is unreachable, so no reachable attack path or demonstrated disclosure has been established.

CVSS severity7.5
High
EPSS probability1.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic weakness in airhost.exe in Zoom Client for Meetings 4.6.11 exposes encrypted data to remote attackers through a fixed AES-CBC IV. The executable supplies the constant 3423423432325249 as the initialization vector for AES-256-CBC instead of generating a fresh unpredictable value. Zoom states that the affected code is unreachable, so no reachable attack path or demonstrated disclosure has been established.

The record

CVE
CVE-2020-11877
Published
Apr 17, 2020
Updated
Aug 4, 2024
Vendor
Zoom Video Communications, Inc.
Product
Zoom Client for Meetings
Classifications
CWE-330
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=4.6.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zoom Video Communications, Inc. · Zoom Client for Meetingsversion=4.6.11

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 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-330Use of Insufficiently Random Values

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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