CVE-2023-30575Public exploitNetwork attack vector

Authenticated connection redirection via Unicode length mismatch

Published Jun 7, 2023 · Updated Oct 10, 2024

Protocol injection in Apache Guacamole 1.5.1 and earlier allows remote authenticated users to redirect server-initiated connections. The Java client counts supplementary Unicode characters as two UTF-16 code units while the C parser expects one code point, letting a crafted image-type parameter terminate its element and inject a connect instruction. Low-privileged web access is required; the injected instruction can replace the legitimate connection destination and parameters.

CVSS severity6.5
Medium
EPSS probability1.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Protocol injection in Apache Guacamole 1.5.1 and earlier allows remote authenticated users to redirect server-initiated connections. The Java client counts supplementary Unicode characters as two UTF-16 code units while the C parser expects one code point, letting a crafted image-type parameter terminate its element and inject a connect instruction. Low-privileged web access is required; the injected instruction can replace the legitimate connection destination and parameters.

The record

CVE
CVE-2023-30575
Published
Jun 7, 2023
Updated
Oct 10, 2024
Vendor
The Apache Software Foundation
Product
Apache Guacamole
Classifications
CWE-131, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 10, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Guacamoleversion=0 <=1.5.1

Published CVSS scores

6.5Apache Software FoundationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-131Incorrect Calculation of Buffer Size
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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