Description
Apache Guacamole 1.1.0 and older may mishandle pointers involved inprocessing data received via RDP static virtual channels. If a userconnects to a malicious or compromised RDP server, a series ofspecially-crafted PDUs could result in memory corruption, possiblyallowing arbitrary code to be executed with the privileges of therunning guacd process.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | Apache Guacamole | Apache Guacamole 1.1.0 and older | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 11 | guacamole-server | 1.3.0-1 | — |
| Debian 9 | guacamole-server | 0.9.9-2+deb9u1 | DLA-2435-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | guacamole-client | No fix yet | — |
| Ubuntu 16.04 LTS | guacamole-client | No fix yet | — |
Advisories 2
- DLA-2435-1 guacamole-server - security update Debian Security (DSA / DLA) · Mar 9, 2026
- VDE-2021-031 MB connect line: Apache Guacamole related vulnerabilities in mbCONNECT24 CERT@VDE · May 14, 2025
References
- https://lists.apache.org/thread.html/rff824b38ebd2fddc726b816f0e509696b83b9f78979d0cd021ca623b%40%3Cannounce.guacamole.apache.org%3E
- [announce] 20200701 [SECURITY] CVE-2020-9498: Apache Guacamole: Dangling pointer in RDP static virtual channel handling mailing-list
- https://research.checkpoint.com/2020/apache-guacamole-rce/
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44525
- [debian-lts-announce] 20201106 [SECURITY] [DLA 2435-1] guacamole-server security update mailing-list
- FEDORA-2020-bfde0ab889 vendor-advisory
- FEDORA-2020-640645e518 vendor-advisory
- [announce] 20210125 Apache Software Foundation Security Report: 2020 mailing-list
- [announce] 20210223 Re: Apache Software Foundation Security Report: 2020 mailing-list