What is the CVSS score of CVE-2019-19781?

CVE-2019-19781 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 94.4%.

Which versions of Application Delivery Controller Firmware are affected by CVE-2019-19781?

CVE-2019-19781 presents critical security risk, a path traversal vulnerability rated CVSS 9.8.

Is there a public PoC exploit available for CVE-2019-19781?

Yes, a public proof-of-concept exploit is available for CVE-2019-19781. Prioritise patching immediately. EPSS: 94.4%.

How to fix or mitigate CVE-2019-19781?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Review file handling controls and restrict upload directories.

Application Delivery Controller Firmware CVE-2019-19781

CRITICAL

Path Traversal (CWE-22)

2019-12-27 cve@mitre.org

Path Traversal Citrix Application Delivery Controller Firmware Netscaler Gateway Firmware Gateway Firmware

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 26, 2026 - 11:19 vuln.today

Added to CISA KEV

Nov 07, 2025 - 19:37 cisa

CISA KEV

PoC Detected

Nov 07, 2025 - 19:37 vuln.today

Public exploit code

CVE Published

Dec 27, 2019 - 14:15 nvd

CRITICAL 9.8

DescriptionNVD

An issue was discovered in Citrix Application Delivery Controller (ADC) and Gateway 10.5, 11.1, 12.0, 12.1, and 13.0. They allow Directory Traversal.

AnalysisAI

Citrix Application Delivery Controller and Gateway contain a directory traversal vulnerability allowing unauthenticated remote code execution, known as 'Shitrix', that triggered a global exploitation crisis in January 2020.

Technical ContextAI

The CWE-22 path traversal in Citrix's NSPPE (Netscaler Perl Extension) allows attackers to write files to arbitrary directories through crafted requests. By writing a Perl template file to the web-accessible cron scripts directory, attackers achieve code execution as the web server user.

RemediationAI

Apply Citrix security updates. Verify no backdoors were installed during the exploitation window. Check for unauthorized users, modified configurations, and web shells. Rotate all credentials accessible from the Citrix appliance.