CVE-2020-9497

Apache Guacamole 1.1.0 and older do not properly validate datareceived from RDP servers via static virtual channels. If a userconnects to a malicious or compromised RDP server, specially-craftedPDUs could result in disclosure of information within the memory ofthe guacd process handling the connection.

Published: 2020-07-02 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-9497 is rated Low Risk (36.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.80%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-9497

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.08% 0.80% +0.71%
2 2025-03-30 0.15% 0.08% -0.07%
3 2025-03-29 — 0.15% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-9497

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.4 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 3.6 [email protected]
1.2 2.0 LOW
AV:L/AC:H/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 1.9 2.9 [email protected]

Weakness enumeration for CVE-2020-9497

OS Trackers for CVE-2020-9497

vendor priority summary link
debian not yet assigned CVE-2020-9497 not yet assigned priority: Debian including 1 source packages (guacamole-server), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2020-9497
ubuntu low CVE-2020-9497 low priority: Ubuntu including 1 source packages (guacamole-client), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 14, needs-triage 3. https://ubuntu.com/security/CVE-2020-9497

Affected software / configurations for CVE-2020-9497

Vendor Product Version Raw CPE
apache guacamole <= 1.1.0 cpe:2.3:a:apache:guacamole:*:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2020-9497

URL Tags
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44525 Third Party Advisory
https://lists.apache.org/thread.html/r066543f0565e97b27c0dfe27e93e8a387b99e1e35764000224ed96e7%40%3Cuser.guacamole.apache.org%3E
https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3E
https://lists.apache.org/thread.html/r181b1d5b1acb31cfa69f41b2c86ed3a2cb0b5bc09c2cbd31e9e7c847%40%3Cuser.guacamole.apache.org%3E
https://lists.apache.org/thread.html/r3f071de70ea1facd3601e0fa894e6cadc960627ee7199437b5a56f7f%40%3Cannounce.apache.org%3E
https://lists.apache.org/thread.html/r65f75d3d65d1af68141f42071ebb27dda24af3e45570e593c1dbd81f%40%3Cannounce.guacamole.apache.org%3E Mailing List Vendor Advisory
https://lists.apache.org/thread.html/r90890afea72a9571d666820b2fe5942a0a5f86be406fa31da3dd0922%40%3Cannounce.apache.org%3E
https://lists.debian.org/debian-lts-announce/2020/11/msg00010.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TVV5K2X4EXSAVUUL7IJ3MUJ3ADWMVSBM/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WNS7UHBOFV6JHWH5XOEZTE3BREGRSSQ3/
https://research.checkpoint.com/2020/apache-guacamole-rce/ Third Party Advisory
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