CVE-2023-30575 | Apache Guacamole: Incorrect calculation of Guacamole protocol element lengths

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.

Published: 2023-06-07 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-30575 is rated Moderate Risk (49/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.16%). Core evidence: EPSS rose +1.00% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.

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-2023-30575

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 0.16% 1.16% +1.00%
2 2026-03-02 0.10% 0.16% +0.05%
3 2025-11-21 0.10%

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-30575

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-30575

OS Trackers for CVE-2023-30575

vendor priority summary link
ubuntu medium CVE-2023-30575 medium priority: Ubuntu including 1 source packages (guacamole-client), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 9, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2023-30575

Affected software / configurations for CVE-2023-30575

Vendor Product Version Raw CPE
apache guacamole < 1.5.2 cpe:2.3:a:apache:guacamole:*:*:*:*:*:*:*:*

References for CVE-2023-30575

URL Tags
https://lists.apache.org/thread/tn63n2lon0h5p45oft834t1dqvvxownv Mailing List Third Party Advisory
cvelogic Threat Intelligence