Cyber Resilience

CVE-2019-12991

RCE in Citrix Netscaler Sd-Wan 10.0.0 – 10.0.8

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCECommand Injection
Published
16 July 2019
Modified
06 November 2025
KEV Added
25 March 2022
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.74 99.4th percentile
Risk Priority 90 floored blend · peak EPSS

Summary

CVE-2019-12991 is a high-severity OS Command Injection (CWE-78) vulnerability in Citrix Netscaler Sd-Wan. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 0.6% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Citrix SD-WAN 10.2.x before 10.2.3 and NetScaler SD-WAN 10.0.x before 10.0.8 contain an improper input validation vulnerability tracked as CVE-2019-12991 and CWE-78. The flaw is one of six related issues in the affected releases and carries a CVSS 3.1 score of 8.8 reflecting network attack vector, low complexity, and low required privileges.

An attacker with low-privileged network access can supply crafted input that bypasses validation checks, enabling authentication bypass followed by remote command execution. Successful exploitation grants full control over the appliance, allowing arbitrary command execution with impacts to confidentiality, integrity, and availability.

Citrix advisory CTX251987 and associated Tenable research note that the issues are resolved in SD-WAN 10.2.3 and NetScaler SD-WAN 10.0.8. Public proof-of-concept code demonstrating the authentication bypass and remote command execution path has been published on Packet Storm.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

Citrix SD-WAN 10.2.x before 10.2.3 and NetScaler SD-WAN 10.0.x before 10.0.8 have Improper Input Validation (issue 5 of 6).

CWE(s)
CWE-78
KEV Date Added
25 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2019-12989Same product: Citrix Netscaler Sd-Wanboth on KEV
CVE-2019-10883Same vendor: Citrix
CVE-2017-6316Same product: Citrix Netscaler Sd-Wanboth on KEV
CVE-2014-6271Same vendor: Citrixboth on KEV
CVE-2014-7169Same vendor: Citrixboth on KEV
CVE-2023-39780Shared CWE-78both on KEV
CVE-2021-20035Shared CWE-78both on KEV
CVE-2026-39808Shared CWE-78both on KEV
CVE-2023-49897Shared CWE-78both on KEV
CVE-2024-6047Shared CWE-78both on KEV

Affected Assets

citrix
netscaler sd-wan
10.0.0 — 10.0.8
citrix
sd-wan
10.2.0 — 10.2.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References