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Nessus Network Monitor CVE-2023-5623

HIGH
Code Injection (CWE-94)
2023-10-26 vulnreport@tenable.com
7.8
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Code injection prevention, sandbox exec
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 7.8 (HIGH). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required.

Exploit ScenarioDerived

A local attacker with access to the system could inject and execute arbitrary code within the application.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.2% exploitation probability (EPSS)

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AnalysisAI

NNM failed to properly set ACLs on its installation directory, which could allow a low privileged user to run arbitrary code with SYSTEM privileges where NNM is installed to a non-standard location. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Code Injection vulnerability could allow attackers to inject and execute arbitrary code within the application.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Never evaluate user-controlled input as code. Use sandboxing, disable dangerous functions, apply strict input validation.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Code Injection (CWE-94), which allows attackers to inject and execute arbitrary code within the application. NNM failed to properly set ACLs on its installation directory, which could allow a low privileged user to run arbitrary code with SYSTEM privileges where NNM is installed to a non-standard location Affected products include: Tenable Nessus Network Monitor.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

DescriptionNVD

NNM failed to properly set ACLs on its installation directory, which could allow a low privileged user to run arbitrary code with SYSTEM privileges where NNM is installed to a non-standard location

Threat Intelligence Overview

EPSS Score
0.2%
Top 95% exploitable
Data Quality
2 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.2%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

39
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +39
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Code Injection CRITICAL

Code injection occurs when an application accepts user input and passes it directly into a language interpreter or evaluator without proper sanitization.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Affected Products (CPE)NVD

cpe:2.3:a:tenable:nessus_network_monitor:*:*:*:*:*:*:*:*
CVE-2021-3711 CRITICAL POC
9.8 Aug 24

In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt(). Rated cri

CVE-2021-3449 MEDIUM
5.9 Mar 25

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. Rated med

CVE-2021-3450 HIGH
7.4 Mar 25

The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain.

CVE-2021-3712 HIGH POC
7.4 Aug 24

ASN.1 strings are represented internally within OpenSSL as an ASN1_STRING structure which contains a buffer holding the

CVE-2023-5622 HIGH
8.8 Oct 26

Under certain conditions, Nessus Network Monitor could allow a low privileged user to escalate privileges to NT AUTHORIT

CVE-2020-5794 HIGH
7.8 Nov 06

A vulnerability in Nessus Network Monitor versions 5.11.0, 5.11.1, and 5.12.0 for Windows could allow an authenticated l

CVE-2021-23840 HIGH
7.5 Feb 16

Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate may overflow the output length argument in some cases

CVE-2023-5624 HIGH
7.2 Oct 26

Under certain conditions, Nessus Network Monitor was found to not properly enforce input validation. Rated high severity

CVE-2020-1971 MEDIUM
5.9 Dec 08

The X.509 GeneralName type is a generic type for representing different types of names. Rated medium severity (CVSS 5.9)

CVE-2021-23841 MEDIUM
5.9 Feb 16

The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based on the issuer

CVE-2024-9158 MEDIUM
4.6 Sep 30

A stored cross site scripting vulnerability exists in Nessus Network Monitor where an authenticated, privileged local at

CVE-2025-24917 HIGH
7.8 May 23

In Tenable Network Monitor versions prior to 6.5.1 on a Windows host, it was found that a non-administrative user could

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