Apache Guacamole: Incorrect calculation of Guacamole protocol element lengths

published 2023-06-07 3 y ago modified 2026-06-17 4 mo ago also BIT-guacamole-2023-30575 , BIT-guacamole-server-2023-30575 , EUVD-2023-34956

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits: 0; none known

Apache Guacamole 1.5.1 and older may incorrectly calculate the lengths of instruction elements sent during the Guacamole protocol handshake, potentially allowing an attacker to inject Guacamole instructions during the handshake through specially-crafted data.

Patch / fix

fixed in 3

bitnami guacamole 1.5.2
bitnami guacamole-server 1.5.2
apache guacamole 1.5.2

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-10-10)

Exploit prediction

1.01% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
OSV	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
bitnami	guacamole	<1.5.2	1.5.2
bitnami	guacamole-server	<1.5.2	1.5.2

Affected products

Apache Software Foundation Apache Guacamole

Classification

Weakness

CWE-131 Incorrect Calculation of Buffer Size

References

lists.apache.org /thread/tn63n2lon0h5p45oft834t1dqvvxownv
vendor-advisory, mailing-list, third-party-advisory, web

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary