Threats / Citrix / CVE-2019-12991
CVE-2019-12991
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Citrix SD-WAN and NetScaler vulnerability
Authenticated command injection vulnerability in Citrix SD-WAN and NetScaler appliances allows authenticated users to execute arbitrary OS commands with elevated privileges.
Verdict
Today item — known-exploited.
An authenticated attacker can inject arbitrary commands through SD-WAN or NetScaler interfaces, achieving remote code execution on affected appliances. Active exploitation in the wild elevates risk despite authentication requirement.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
2 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25).
Probability (EPSS)
EPSS 0.74512 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Citrix, SD-WAN and NetScaler. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I authenticate to the appliance management interface using valid credentials.
Business
Insider threat or compromised account credentials create initial access vector.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I inject OS commands into input fields that lack proper sanitization.
Business
Command injection flaws bypass application logic and security controls.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary commands with the appliance process privileges.
Business
Attacker gains code execution on critical network infrastructure.
4
Data at risk — exfiltration narrative 4
Attacker
I establish persistence or pivot to connected networks.
Business
SD-WAN and NetScaler appliances control traffic routing; compromise enables lateral movement and data exfiltration.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05