CVE-2020-11997Network attack vector

Cross-user history disclosure via inconsistent visibility checks

Published Jan 19, 2021 · Updated Aug 4, 2024

Information disclosure in Apache Guacamole 1.2.0 and earlier allows remote authenticated users to view other users' connection history. The connection-history authorization path returns records based on shared connection access without enforcing visibility over each recorded user. Exploitation requires multiple users to share a connection and exposes other users' identities and source IP addresses.

CVSS severity4.3
Medium
EPSS probability1.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Apache Guacamole 1.2.0 and earlier allows remote authenticated users to view other users' connection history. The connection-history authorization path returns records based on shared connection access without enforcing visibility over each recorded user. Exploitation requires multiple users to share a connection and exposes other users' identities and source IP addresses.

The record

CVE
CVE-2020-11997
Published
Jan 19, 2021
Updated
Aug 4, 2024
Vendor
The Apache Software Foundation
Product
Apache Guacamole
Classifications
CWE-276
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 19, 2021CVE 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=Apache Guacamole 1.2.0 and older

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Guacamoleversion=Apache Guacamole 1.2.0 and older

Published CVSS scores

4.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:S/C:P/I:N/A:N
4.3NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-276Incorrect Default Permissions

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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