Citrix NetScaler ADC/NetScaler Gateway prior 13.1-37.236-FIPS/13.1-59.19/14.1-47.46 memory corruption

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.7$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Citrix NetScaler ADC and NetScaler Gateway. Affected by this issue is some unknown functionality. The manipulation leads to memory corruption. This vulnerability is listed as CVE-2025-6543. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Citrix NetScaler ADC and NetScaler Gateway and classified as critical. This issue affects an unknown functionality. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Memory overflow vulnerability leading to unintended control flow and Denial of Service in NetScaler ADC and NetScaler Gateway when configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server

The advisory is shared at support.citrix.com. The identification of this vulnerability is CVE-2025-6543 since 06/23/2025. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/22/2025).

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 240342 (NetScaler ADC and NetScaler Gateway Memory Overflow (CTX694788)), which helps to determine the existence of the flaw in a target environment. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 06/30/2025 with a due date of 07/21/2025:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Upgrading to version 13.1-37.236-FIPS, 13.1-59.19 or 14.1-47.46 eliminates this vulnerability.

The vulnerability is also documented in the databases at Zero-Day.cz (1014), Tenable (240342) and EUVD (EUVD-2025-19085). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 8.9
VulDB Meta Temp Score: 8.7

VulDB Base Score: 8.1
VulDB Temp Score: 7.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Attacked

EPSS Score: 🔒
EPSS Percentile: 🔒

KEV Added: 🔒
KEV Due: 🔒
KEV Remediation: 🔒
KEV Ransomware: 🔒
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Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 240342
Nessus Name: NetScaler ADC and NetScaler Gateway Memory Overflow (CTX694788)

Zero-Day.cz: 🔒

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: NetScaler ADC/NetScaler Gateway 13.1-37.236-FIPS/13.1-59.19/14.1-47.46

Timelineinfo

06/23/2025 CVE reserved
06/25/2025 +2 days Advisory disclosed
06/25/2025 +0 days VulDB entry created
10/22/2025 +119 days VulDB entry last update

Sourcesinfo

Vendor: citrix.com

Advisory: CTX694788
Status: Confirmed

CVE: CVE-2025-6543 (🔒)
GCVE (CVE): GCVE-0-2025-6543
GCVE (VulDB): GCVE-100-313853
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 06/25/2025 15:07
Updated: 10/22/2025 04:09
Changes: 06/25/2025 15:07 (67), 06/25/2025 16:07 (1), 06/25/2025 23:09 (2), 06/27/2025 08:18 (6), 06/30/2025 21:38 (9), 07/01/2025 03:52 (1), 10/22/2025 04:09 (11)
Complete: 🔍
Cache ID: 216:2F3:103

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