CVE-2020-11997
Updated guacd packages fix security vulnerabilities
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
4.3
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
CVE-2020-11997- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:P/I:N/A:N - Weakness
- CWE-276
- Updated
- 2026-11-02
CVE List No score
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
CVE-2020-11997- Updated
- 2026-11-02
EUVDEUVD-2020-4314 No score
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
EUVD-2020-4314- Updated
- 2026-11-03
OSV
4.3
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
CVE-2020-11997- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-11997
4.3
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
UBUNTU-CVE-2020-11997- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVBIT-guacamole-2020-11997 No score
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
BIT-guacamole-2020-11997- Updated
- 2026-11-02
OSVBIT-guacamole-server-2020-11997 No score
Apache Guacamole 1.2.0 and earlier do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users.
- Record
BIT-guacamole-server-2020-11997- Updated
- 2026-11-02
OSVMGASA-2021-0272 No score
Updated guacd packages fix security vulnerabilities
Prior to 1.0.0, Apache Guacamole used a cookie for client-side storage of the user's session token. This cookie lacked the "secure" flag, which could allow an attacker eavesdropping on the network to intercept the user's session token if unencrypted HTTP requests are made to the same domain (CVE-2018-1340).
Apache Guacamole 1.1.0 and older do not properly validate data received from RDP servers via static virtual channels. If a user connects to a malicious or compromised RDP server, specially-crafted PDUs could result in disclosure of information within the memory of the guacd process handling the connection (CVE-2020-9497).
Apache Guacamole 1.1.0 and older may mishandle pointers involved in processing data received via RDP static virtual channels. If a user connects to a malicious or compromised RDP server, a series of specially-crafted PDUs could result in memory corruption, possibly allowing arbitrary code to be executed with the privileges of the running guacd process (CVE-2020-9498).
Apache Guacamole 1.2.0 and older do not consistently restrict access to connection history based on user visibility. If multiple users share access to the same connection, those users may be able to see which other users have accessed that connection, as well as the IP addresses from which that connection was accessed, even if those users do not otherwise have permission to see other users (CVE-2020-11997).
This is an update of guacd to latest version to fix security issues. We also updated util-linux and ossp_uuid to make them co installable as guacd requires ossp_uuid.
- Record
MGASA-2021-0272- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
guacamoleBitnami |
before 1.2.0 | 1.2.0 |
guacamole-serverBitnami |
before 1.2.0 | 1.2.0 |
guacdMageia:7 From an advisory covering 4 CVEs |
before 1.3.0-1.mga7 | 1.3.0-1.mga7 |
util-linuxMageia:7 From an advisory covering 4 CVEs |
before 2.33.2-1.1.mga7 | 2.33.2-1.1.mga7 |
ossp_uuidMageia:7 From an advisory covering 4 CVEs |
before 1.6.2-21.1.mga7 | 1.6.2-21.1.mga7 |
guacamole-serverUbuntu:16.04:LTS |
All versions, plus listed versions 0.8.3-1build20.8.3-2 |
None known |
guacamole-serverUbuntu:18.04:LTS |
All versions, plus listed versions 0.9.9-20.9.9-2build1 |
None known |
guacamole-serverUbuntu:22.04:LTS |
All versions, plus listed versions 1.3.0-11.3.0-1build11.3.0-1.1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases, products | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-11997 is a medium vulnerability (CVSS 4.3) in Apache Guacamole, published January 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.26%, the 69th percentile. Fixed in guacamole 1.2.0.
References
lists.apache.org/thread.html/r1a9ae9d1608c9f846875c4191cd738f95543d1be06b52dc1320e8117%40%3Cannounce.guacamole.apache.org%3E
advisories.mageia.org/MGASA-2021-0272.html
bugs.mageia.org/show_bug.cgi?id=28158
bugs.mageia.org/show_bug.cgi?id=24509
bugs.mageia.org/show_bug.cgi?id=27593
lists.fedoraproject.org/archives/list/[email protected]/thread/32RWZPQ7FRP73BVKOQK27XV6TX47TT3R