Security Resilience

CVE-2023-43826

Memory Safety in Apache Guacamole ≤ 1.5.3

Memory Safety
Published
19 December 2023
Modified
13 February 2025
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0089 59th percentile
Risk Priority 57 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-43826 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Apache Guacamole. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSA Secrets (T1003.004); ranked in the top 41% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

Apache Guacamole 1.5.3 and older do not consistently ensure that values received from a VNC server will not result in integer overflow. If a user connects to a malicious or compromised VNC server, specially-crafted data could result in memory corruption,…

more

possibly allowing arbitrary code to be executed with the privileges of the running guacd process. Users are recommended to upgrade to version 1.5.4, which fixes this issue.

CWE(s)
CWE-190

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
attack.mitre.org →
T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-35164Same product: Apache Guacamole
CVE-2023-30575Same product: Apache Guacamole
CVE-2023-30576Same product: Apache Guacamole
CVE-2026-93546Same vendor: Apache
CVE-2025-52520Same vendor: Apache
CVE-2025-66168Same vendor: Apache
CVE-2026-41602Same vendor: Apache
CVE-2026-95616Same vendor: Apache
CVE-2025-55753Same vendor: Apache
CVE-2026-41605Same vendor: Apache

Affected Assets

apache
guacamole
≤ 1.5.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
blocks

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References