CVE-2025-6543
Citrix NetScaler ADC and Gateway Buffer Overflow V - [Actively Exploited]
Description
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
INFO
Published Date :
June 25, 2025, 1:15 p.m.
Last Modified :
July 1, 2025, 6:19 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
5.9
Exploitability Score :
3.9
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.
Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788 ; https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/ ; https://nvd.nist.gov/vuln/detail/CVE-2025-6543
Public PoC/Exploit Available at Github
CVE-2025-6543 has a 9 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
Affected Products
The following products are affected by CVE-2025-6543
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-6543.
| URL | Resource |
|---|---|
| https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788 | Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Python
Multi-host, multi-port scanner and auditor for CVE-2025-6543-affected NetScaler devices. Supports SNMP and SSH enumeration with optional CSV reporting and exploit stubs.
Python
详细讲解CitrixBleed 2 — CVE-2025-5777（越界泄漏）PoC 和检测套件
Python
Citrix Bleed 2 PoC
Python
Script para determinar si Citrix es vulnerable al CVE-2025-6543
Python
None
HTML Python Shell
CISA Bot is a GitHub bot that automatically monitors the Cybersecurity and Infrastructure Security Agency (CISA) Known Exploited Vulnerabilities (KEV) Catalog. When new vulnerabilities are published in the KEV, the bot creates GitHub issues in this repository with detailed information about each vulnerability.
Python
Technical notes, AD pentest methodology, list of tools, scripts and Windows commands that I find useful during internal penetration tests and assumed breach exercises (red teaming)
PowerShell C#
📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.
security cve exploit poc vulnerability
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-6543 vulnerability anywhere in the article.
-
BleepingComputer
Citrix Bleed 2 exploited weeks before PoCs as Citrix denied attacks
A critical Citrix NetScaler vulnerability, tracked as CVE-2025-5777 and dubbed "CitrixBleed 2," was actively exploited nearly two weeks before proof-of-concept (PoC) exploits were made public, despite ... Read more
-
The Hacker News
CISA Adds Citrix NetScaler CVE-2025-5777 to KEV Catalog as Active Exploits Target Enterprises
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Thursday added a critical security flaw impacting Citrix NetScaler ADC and Gateway to its Known Exploited Vulnerabilities (KEV) cata ... Read more
-
The Hacker News
CISA Adds Citrix NetScaler CVE-2025-5777 to KEV Catalog as Active Exploits Target Enterprises
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Thursday added a critical security flaw impacting Citrix NetScaler ADC and Gateway to its Known Exploited Vulnerabilities (KEV) cata ... Read more
-
The Register
Now everybody but Citrix agrees that CitrixBleed 2 is under exploit
The US Cybersecurity and Infrastructure Security Agency has added its weighty name to the list of parties agreeing that CVE-2025-5777, dubbed CitrixBleed 2 by one researcher, has been under exploitati ... Read more
-
The Register
Now everybody but Citrix agrees that CitrixBleed 2 is under exploit
The US Cybersecurity and Infrastructure Security Agency has added its weighty name to the list of parties agreeing that CVE-2025-5777, dubbed CitrixBleed 2 by one researcher, has been under exploitati ... Read more
-
The Hacker News
Critical mcp-remote Vulnerability Enables Remote Code Execution, Impacting 437,000+ Downloads
Jul 10, 2025Ravie LakshmananVulnerability / AI Security Cybersecurity researchers have discovered a critical vulnerability in the open-source mcp-remote project that could result in the execution of ... Read more
-
The Hacker News
AMD Warns of New Transient Scheduler Attacks Impacting a Wide Range of CPUs
Jul 10, 2025Ravie LakshmananVulnerability / Hardware Security Semiconductor company AMD is warning of a new set of vulnerabilities affecting a broad range of chipsets that could lead to information ... Read more
-
Daily CyberSecurity
Citrix Warns of Privilege Escalation Vulnerability in Windows Virtual Delivery Agent (CVE-2025-6759)
Citrix has issued a security advisory concerning a newly identified local privilege escalation vulnerability affecting its Windows Virtual Delivery Agent (VDA), which is a core component of Citrix Vir ... Read more
-
Cyber Security News
PoC Exploits for CitrixBleed2 Flaw Released – Attackers Can Exfiltrate 127 Bytes Per Request
Security researchers have released proof-of-concept exploits for a critical vulnerability dubbed “CitrixBleed2” affecting Citrix NetScaler ADC and Gateway products. The vulnerability, tracked as CVE-2 ... Read more
-
The Hacker News
RondoDox Botnet Exploits Flaws in TBK DVRs and Four-Faith Routers to Launch DDoS Attacks
Cybersecurity researchers are calling attention to a malware campaign that's targeting security flaws in TBK digital video recorders (DVRs) and Four-Faith routers to rope the devices into a new botnet ... Read more
-
The Hacker News
CISA Adds Four Critical Vulnerabilities to KEV Catalog Due to Active Exploitation
Cyber Attacks / Vulnerability The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Monday added four security flaws to its Known Exploited Vulnerabilities (KEV) catalog, citing evidence ... Read more
-
The Hacker News
CISA Adds Four Critical Vulnerabilities to KEV Catalog Due to Active Exploitation
Jul 08, 2025Ravie LakshmananCyber Attacks / Vulnerability The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Monday added four security flaws to its Known Exploited Vulnerabilities ... Read more
-
The Register
CitrixBleed 2 exploits are on the loose as security researchers yell and wave their hands
Multiple exploits are circulating for CVE-2025-5777, a critical bug in Citrix NetScaler ADC and NetScaler Gateway dubbed CitrixBleed 2, and security analysts are warning a "significant portion" of use ... Read more
-
Help Net Security
Week in review: Sudo local privilege escalation flaws fixed, Google patches actively exploited Chrome
Here’s an overview of some of last week’s most interesting news, articles, interviews and videos: Sudo local privilege escalation vulnerabilities fixed (CVE-2025-32462, CVE-2025-32463) If you haven’t ... Read more
-
security.nl
Duizenden NetScaler-servers kwetsbaar voor CitrixBleed2, details snel openbaar
Duizenden NetScaler-servers bevatten nog altijd een kritieke kwetsbaarheid aangeduid als "CitrixBleed2", waardoor ze in het ergste geval zijn over te nemen, en een securitybedrijf heeft aangegeven vol ... Read more
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The Hacker News
Critical Sudo Vulnerabilities Let Local Users Gain Root Access on Linux, Impacting Major Distros
Cybersecurity researchers have disclosed two security flaws in the Sudo command-line utility for Linux and Unix-like operating systems that could enable local attackers to escalate their privileges to ... Read more
-
The Hacker News
Chinese Hackers Exploit Ivanti CSA Zero-Days in Attacks on French Government, Telecoms
The French cybersecurity agency on Tuesday revealed that a number of entities spanning governmental, telecommunications, media, finance, and transport sectors in the country were impacted by a malicio ... Read more
-
The Hacker News
Critical Cisco Vulnerability in Unified CM Grants Root Access via Static Credentials
Vulnerability / Network Security Cisco has released security updates to address a maximum-severity security flaw in Unified Communications Manager (Unified CM) and Unified Communications Manager Sessi ... Read more
-
BleepingComputer
Citrix warns of login issues after NetScaler auth bypass patch
Citrix warns that patching recently disclosed vulnerabilities that can be exploited to bypass authentication and launch denial-of-service attacks may also break login pages on NetScaler ADC and Gatewa ... Read more
-
The Hacker News
Critical Vulnerability in Anthropic's MCP Exposes Developer Machines to Remote Exploits
Cybersecurity researchers have discovered a critical security vulnerability in artificial intelligence (AI) company Anthropic's Model Context Protocol (MCP) Inspector project that could result in remo ... Read more
-
Cyber Security News
CISA Warns of Citrix NetScaler ADC and Gateway Vulnerability Actively Exploited in Attacks
CISA has issued an urgent warning regarding a critical buffer overflow vulnerability in Citrix NetScaler ADC and Gateway products, designated as CVE-2025-6543. Added to CISA’s Known Exploited Vulnerab ... Read more
-
TheCyberThrone
CISA Adds Critical Citrix NetScaler Vulnerability to KEV Catalog
Skip to contentOn June 30, 2025, the Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2025-6543, a critical buffer overflow vulnerability in Citrix NetScaler ADC and Gateway, to its K ... Read more
-
Daily CyberSecurity
Urgent Citrix NetScaler Alert: Critical Memory Overflow Flaw (CVE-2025-6543, CVSS 9.2) Actively Exploited on 2,100+ Unpatched Appliances
A critical security flaw tracked as CVE-2025-6543 is being actively exploited in the wild, prompting urgent warnings from Citrix and inclusion in CISA’s Known Exploited Vulnerabilities (KEV) Catalog. ... Read more
-
Cyber Security News
2100+ Citrix Servers Vulnerable to Actively Exploited Bypass Authentication Vulnerability
Over 2,100 vulnerable Citrix NetScaler servers remain exposed to active exploitation, despite patches being available for critical vulnerabilities that allow attackers to bypass authentication mechani ... Read more
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Help Net Security
CitrixBleed 2 might be actively exploited (CVE-2025-5777)
While Citrix has observed some instances where CVE-2025-6543 has been exploited on vulnerable NetScaler networking appliances, the company still says that they don’t have evidence of exploitation for ... Read more
-
security.nl
'Tientallen Nederlandse Citrix-servers bevatten kritieke kwetsbaarheden'
Tientallen Nederlandse Citrix-servers bevatten kritieke kwetsbaarheden, zo laat The Shadowserver Foundation vandaag weten. Het gaat onder andere om een actief misbruikt beveiligingslek. De afgelopen w ... Read more
-
BleepingComputer
Over 1,200 Citrix servers unpatched against critical auth bypass flaw
Over 1,200 Citrix NetScaler ADC and NetScaler Gateway appliances exposed online are unpatched against a critical vulnerability believed to be actively exploited, allowing threat actors to bypass authe ... Read more
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Daily CyberSecurity
Citrix Bleed 2: ReliaQuest Warns of Active Exploitation in NetScaler Gateway Vulnerability
A newly discovered vulnerability—CVE-2025-5777, now dubbed Citrix Bleed 2—is raising serious security alarms. According to ReliaQuest, attackers are actively exploiting this vulnerability in the wild ... Read more
-
security.nl
Securitybedrijf meldt mogelijk misbruik van nieuw CitrixBleed-lek
Een nieuwe kwetsbaarheid in NetScaler ADC en NetScaler Gateway, die de naam CitrixBleed 2 heeft gekregen, wordt mogelijk actief misbruik bij aanvallen, zo stelt securitybedrijf ReliaQuest. NetScaler z ... Read more
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Daily CyberSecurity
Cisco ISE/ISE-PIC Alert: Two Critical RCE Flaws (CVSS 10.0) Allow Unauthenticated Root Access
Cisco has disclosed two critical vulnerabilities in its Identity Services Engine (ISE) and Passive Identity Connector (ISE-PIC) that could allow unauthenticated, remote attackers to execute arbitrary ... Read more
-
Daily CyberSecurity
Urgent Citrix NetScaler Alert: Critical Memory Overflow Flaw (CVE-2025-6543, CVSS 9.2) Actively Exploited
Citrix has issued a critical advisory for CVE-2025-6543, a memory overflow vulnerability that impacts NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway). According to ... Read more
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security.nl
Citrix waarschuwt voor misbruik van kritiek lek in NetScaler ADC en Gateway
Citrix waarschuwt organisaties voor actief misbruik van een kritieke kwetsbaarheid in NetScaler ADC en NetScaler Gateway. Het gaat om een buffer overflow die volgens Citrix tot "unintended control flo ... Read more
-
The Register
Citrix bleeds again: This time a zero-day exploited - patch now
Hot on the heels of patching a critical bug in Citrix-owned Netscaler ADC and NetScaler Gateway that one security researcher dubbed "CitrixBleed 2," the embattled networking device vendor today issued ... Read more
-
BleepingComputer
Citrix warns of NetScaler vulnerability exploited in DoS attacks
Citrix is warning that a vulnerability in NetScaler appliances tracked as CVE-2025-6543 is being actively exploited in the wild, causing devices to enter a denial of service condition. "Exploits of CV ... Read more
-
The Hacker News
Citrix Releases Emergency Patches for Actively Exploited CVE-2025-6543 in NetScaler ADC
Vulnerability / Network Security Citrix has released security updates to address a critical flaw affecting NetScaler ADC that it said has been exploited in the wild. The vulnerability, tracked as CVE- ... Read more
-
Cyber Security News
Citrix NetScaler ADC and Gateway Vulnerability Actively Exploited in the Wild
Cloud Software Group has issued an urgent security advisory warning customers about a critical memory overflow vulnerability in NetScaler ADC and Gateway products, which could enable denial-of-service ... Read more
The following table lists the changes that have been made to the
CVE-2025-6543 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 01, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:* versions from (including) 13.1 up to (excluding) 13.1-59.19 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:* versions from (including) 13.1 up to (excluding) 13.1-37.236 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:* versions from (including) 14.1 up to (excluding) 14.1-47.46 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:* versions from (including) 13.1 up to (excluding) 13.1-37.236 Added CPE Configuration OR *cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:* versions from (including) 13.1 up to (excluding) 13.1-59.19 *cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:* versions from (including) 14.1 up to (excluding) 14.1-47.46 Added Reference Type Citrix Systems, Inc.: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788 Types: Vendor Advisory -
CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725
Jul. 01, 2025
Action Type Old Value New Value Added Date Added 2025-06-30 Added Due Date 2025-07-21 Added Required Action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Added Vulnerability Name Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability -
New CVE Received by [email protected]
Jun. 25, 2025
Action Type Old Value New Value Added Description 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 Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-119 Added Reference https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-6543 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-6543
weaknesses.