Threats / Citrix / CVE-2019-13608
CVE-2019-13608
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Citrix StoreFront Server vulnerability
Citrix StoreFront Server contains an XML External Entity (XXE) vulnerability allowing unauthenticated attackers to retrieve sensitive information. The flaw has been exploited in the wild and linked to ransomware campaigns.
Verdict
Today item, not a backlog item.
An unauthenticated remote attacker can exploit XXE processing in StoreFront Server to exfiltrate sensitive data without authentication. Active exploitation and ransomware deployment indicate high operational risk despite the absence of a CVSS score.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
4 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 2021-11-03), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.28032 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Citrix, StoreFront Server. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-611 XML External Entity (XXE) — weakness family: Web / client.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 craft a malicious XML payload with external entity references targeting the StoreFront Server endpoint.
Business
Attackers gain initial reconnaissance capability to map internal systems and extract configuration data.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I submit the XXE payload to retrieve local files and internal service information from the compromised server.
Business
Sensitive credentials, API keys, and system architecture details are exposed to the attacker.
3
Lateral reach — past segmentation narrative 3
Attacker
I use exfiltrated information to identify additional targets and escalate access within the environment.
Business
The breach expands laterally across infrastructure, increasing the attack surface.
4
Data at risk — exfiltration narrative 4
Attacker
I deploy ransomware or data exfiltration tools using the compromised StoreFront Server as a pivot point.
Business
Critical business systems become encrypted or data is stolen, resulting in operational shutdown and financial extortion.
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