Skip to main content

Netscaler Gateway CVE-2023-4967

HIGH
Buffer Overflow (CWE-119)
2023-10-27 secure@citrix.com
7.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, buffer size validation
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

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

Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available.

Exploit ScenarioDerived

A remote attacker could corrupt memory to execute arbitrary code or crash the application by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.9% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

Denial of Service in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA Virtual Server. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use memory-safe languages or bounds-checking. Enable ASLR, DEP/NX, stack canaries. Use safe string functions.

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 Buffer Overflow (CWE-119), which allows attackers to corrupt memory to execute arbitrary code or crash the application. Denial of Service in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA Virtual Server Affected products include: Citrix Netscaler Application Delivery Controller, Citrix Netscaler Gateway.

Know when Netscaler Gateway gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

DescriptionNVD

Denial of Service in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA Virtual Server

Threat Intelligence Overview

EPSS Score
0.9%
Top 45% exploitable
Exploit
POC
Public exploit code exists
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 Yes
EPSS 0.9%
Patch available No
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
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact· derived
Medium

Priority Score

59
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +38
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)NVD

cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*
cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*
cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*
CVE-2023-3519 CRITICAL POC
9.8 Jul 19

Citrix NetScaler ADC and Gateway contain an unauthenticated remote code execution vulnerability exploited massively in s

CVE-2023-4966 HIGH POC
7.5 Oct 10

Sensitive information disclosure in Citrix NetScaler ADC and NetScaler Gateway - widely known as 'Citrix Bleed' - allows

CVE-2025-5777 CRITICAL POC
9.3 Jun 17

Memory overread in Citrix NetScaler ADC and NetScaler Gateway (versions before 14.1-43.56 and 13.1-58.32) lets remote un

CVE-2026-19490 CRITICAL POC
9.3 Aug 19

Unauthenticated information disclosure in Citrix NetScaler ADC and NetScaler Gateway (versions 14.1 before 73.32 and 13.

CVE-2025-6543 CRITICAL POC
9.8 Jun 25

Citrix NetScaler ADC and Gateway contain a memory overflow vulnerability (CVE-2025-6543, CVSS 9.8) leading to unintended

CVE-2026-8452 HIGH POC
8.8 Jun 30

Denial of service and memory corruption in Citrix NetScaler ADC and NetScaler Gateway allows remote unauthenticated atta

CVE-2026-8451 HIGH POC
8.8 Jun 30

Memory overread in Citrix NetScaler ADC and NetScaler Gateway lets remote attackers read out-of-bounds memory when the a

CVE-2025-5349 HIGH POC
8.8 Jun 17

Improper access control vulnerability in NetScaler ADC and NetScaler Gateway management interfaces that allows unauthent

CVE-2026-8655 HIGH
8.8 Jun 30

Denial of service in Citrix NetScaler ADC and NetScaler Gateway stems from multiple memory overflow conditions that prod

CVE-2026-13474 HIGH
8.7 Jun 30

Denial of service in Citrix NetScaler ADC and NetScaler Gateway allows remote attackers to crash or render unresponsive

CVE-2020-8247 HIGH
8.8 Sep 18

Citrix ADC and Citrix Gateway 13.0 before 13.0-64.35, Citrix ADC and NetScaler Gateway 12.1 before 12.1-58.15, Citrix AD

CVE-2024-8534 HIGH
8.4 Nov 12

Memory safety vulnerability leading to memory corruption and Denial of Service in NetScaler ADC and Gateway if the appli

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy