Citrix and VDI Breakout Testing
You publish one application and assume that is all a user gets. We start from that published application and see how much of the desktop, the file system and the domain is reachable from it. CREST-certified testers, fixed price from £2,930, scoped in 24 hours.
- Unlimited retesting
- No rescheduling or cancellation fees
- Fixed quote within 24 hours
“I would highly recommend EJN Labs to any organisation seeking reliable, detailed, and well-managed penetration testing services, particularly for government or enterprise-level projects.”
Imran SaghirProject Lead, SquareOne“There wasn’t another company we could find that could deliver what we needed in the timeframe we needed. The client loved it, and we got instant ROI from the engagement.”
Dan WilcocksonCo-Founder, CelloriA published application is a window onto a full Windows session. Every dialog inside it, every help file, every embedded browser control and every macro engine is a potential route out of the application and into the desktop behind it.
Published does not mean contained
Once there, the questions are the familiar Windows ones with a twist: what the session account can read, which drives and clipboard channels are redirected between the endpoint and the server, and whether profile and policy controls actually apply to this user.
The third part is what the breakout reaches. These servers usually sit in a trusted zone with line of sight to file shares, management tooling and domain controllers, which is why a breakout is rarely the end of the report.
ISO 27001, SOC 2, PCI DSS and Cyber Essentials Plus audits accept manual penetration test evidence. Scan-only evidence is generally insufficient.
BREAKOUT SPECIFICS
What We Actually Test in a Citrix or VDI Environment
Ten areas that apply because users reach the estate through a published desktop or application, on top of the standard internal checks. Every finding is verified, reproducible and mapped to CIS benchmarks, CWE and CVSS 3.1.
Application escape
Dialogs, help systems, embedded browsers, macro engines and file handlers used to reach a shell or explorer.
Policy enforcement
Whether published application restrictions, AppLocker or similar controls apply to the session in practice.
File system and registry
What the session account can read and write locally, including other user profiles and application data.
Redirection channels
Drive, clipboard, printer and USB redirection between the endpoint and the session, in both directions.
Session isolation
What one user session can see of another on the same host, including temporary files and processes.
Privilege escalation
Local escalation on the session host, service permissions, scheduled tasks and installed agents.
Credential exposure
Cached credentials, saved sessions, scripts with passwords and what a memory read would return.
Onward movement
What the session host reaches: shares, management tooling, databases and domain infrastructure.
Gateway and access control
Storefront or gateway authentication, multi-factor coverage, and enumeration of published resources.
Image and patching posture
The gold image build, patch level, installed agents and the drift between images.
METHODOLOGY
What a Citrix and VDI finding looks like
Written the way a finding appears in our reports. The example below is reconstructed from publicly documented research, with hosts, paths and identifiers redacted. We do not republish client findings, named or anonymised.
Session token disclosure on the gateway, then a breakout from a published application
- Affected
- The gateway at [redacted] and a published Office application on the same session host farm.
- What we found
- The gateway returned valid session material in response to an unauthenticated request, which we replayed to reach an authenticated session with no credentials and no multi-factor prompt. Inside that session, a published application gave us a file dialog, filesystem browsing and then a command shell.
- Why it matters
- Authenticated access from the internet without credentials, followed by command execution on a domain joined session host shared by every user of that published application.
- Fix
- Patch the gateway and terminate all existing sessions, because patching alone does not invalidate tokens already taken. Lock published applications down with application control, disable file dialog navigation, and remove the session host from broad domain groups.
Reconstructed from public research: CVE-2023-4966, known as Citrix Bleed, sensitive information disclosure in NetScaler ADC and Gateway, CVSS 3.1 base score 9.4.
Citrix Penetration Testing: From Scope to Attestation
CREST-aligned methodology built on OWASP Web Security Testing Guide, OWASP ASVS, NIST SP 800-115, and PTES. Each finding maps to all four standards plus your specific compliance regime.
Reconnaissance
Application mapping, technology fingerprinting, content discovery, parameter enumeration, authentication-flow analysis, role-matrix construction.
Vulnerability Assessment
Authenticated and unauthenticated automated scanning across every user role, plus targeted manual checks for known weakness patterns.
Manual Exploitation
Hands-on testing by a CREST-certified pentester. Business-logic exploitation, chained vulnerabilities, privilege escalation, impact validation.
Reporting + Retest
Executive summary, technical report with CVSS scores and reproduction steps, walkthrough call, free retest after remediation, attestation letter.
CREDENTIALS
Verified Accreditations Auditors Accept
Every credential below is independently verifiable. UK procurement teams, FCA supervisors, ISO 27001 / SOC 2 auditors, and cyber insurance underwriters all recognise these standards.
GET YOUR QUOTE
Get a CREST Citrix assessment pen test quote in 24 hours
A fixed-price quote back in one business day, from a named CREST assessor. No sales pipeline, no chasing.
- CREST and IASME accredited. Testing your auditors and clients already recognise.
- Fast-track testing within 24 hours where required. Free retest of every fix included.
- Live findings via your client portal, not a four-week PDF.
- Fixed price from £2,930 for a small, single-scope engagement, agreed up front. Most engagements run £4,320 and up. No day-rate surprises.
Dan WilcocksonCo-Founder, CelloriUnder NDA Further named references available on a scoping call.
- We reply within one business day with a fixed-price quote from a named CREST assessor.
- You approve the scope and we book a start date, usually within 24 hours.
- Live findings land in your client portal as we test, with a free retest of every fix.
Get your fixed pen test quote in 24 hours
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COMPLIANCE READY
Reports Mapped to Every Framework
Findings are explicitly tagged to the relevant control reference. Your audit team submits the report directly without translation work.
ISO 27001:2022
Annex A.8.8 management of technical vulnerabilities plus A.5.15-5.18 and A.8.2-8.5 access control validation.
SOC 2 Type I & II
CC6 logical access, CC7 system operations, CC8 change management evidence.
PCI DSS
Requirement 11.4 application penetration testing across cardholder data environments, including ecommerce penetration testing for online retail platforms.
FCA SYSC
SYSC 4.1.1R, 6.1.1R, 13 mapped to each finding for FCA-regulated firms.
UK GDPR
Article 32 effectiveness testing, customer-data security controls, ICO-acceptable evidence.
Cyber Essentials Plus
Direct certification through our IASME body status, single-vendor delivery.
PRICING
Transparent Citrix Penetration Testing Pricing
Pricing depends on the number of devices, rule sets and published applications in scope, and how many entry points are exposed to the internet. The day count flexes; the included deliverables stay the same across all engagements.
2 to 3 days
Single user role, basic CRUD application, marketing website with auth. Typically 5-day engagement.
Get a fixed quote3 to 5 days
Multi-role SaaS, business application with payment integration. Typically 8-12 day engagement.
Get a fixed quote5 to 7 days
Multi-tenant platform, complex authorisation matrix, integration-heavy applications. 15-20 day engagement.
Get a fixed quotePart of Technologies We Pen Test. These are examples of the stacks we publish pages for, not a complete list. If yours is not here we still test it. Related pages:
BY SECTOR
Citrix Penetration Testing for Your Sector
Sector-specialist scoping for UK businesses with sector-specific compliance regimes and threat models.
Fintech & FCA-Regulated
FCA SYSC, Open Banking FAPI 1.0, PSD2 SCA, payment-flow scrutiny, KYC/AML testing.
Fintech sector pageSaaS Companies
SOC 2 Type I & II evidence, multi-tenant boundaries, role escalation, customer-tenant isolation.
SaaS sector pageLaw Firms
SRA Cyber Standard, privileged data, conveyancing fraud defence, partner-tier procurement.
Law firm sector pageHealthcare
NHS DTAC, DSP Toolkit v6, UK GDPR Article 32, EHR systems, telehealth platforms.
Healthcare sector pageInsurance
FCA / PRA Operational Resilience, cyber underwriting, claims data, broker portals.
Insurance sector pagePublic Sector
CCS / G-Cloud framework, NCSC-aligned, citizen-facing services, PSN-compliance scrutiny.
Public sector pageWHY EJN LABS
What You Get From Citrix Penetration Testing
Six concrete differentiators competitors don’t all match.
CREST-Certified Testers, Verifiable
Every test by a CREST-certified pen tester (CRT, CCT APP, CCT INF where applicable). Verify our company status at crest-approved.org.
24-Hour Startup, Where Required
From signed scope to active testing in a single business day for incident response, audit deadlines, or regulator-driven timelines.
Live Findings, Not 4-Week PDFs
Critical issues reported during testing through your client portal. Your team remediates while testing continues.
Audit-Ready Reports
Executive summary plus full technical report with CVSS scores and explicit framework mappings (ISO 27001, SOC 2, PCI DSS, FCA SYSC).
Free Retests, Standard
Verify remediation of every finding before close-out. Letter of attestation for audit submission included. Most competitors charge £1,500-£3,000 per retest.
UK-Based CREST Testers
Every engagement performed by vetted, UK-based CREST-certified testers, matched to your needs, security clearance, and compliance scope.
FAQ
Frequently Asked
Do we need to give you a laptop?
No. A published application or desktop reachable from our position is enough, with a standard user account.
Is this Citrix only?
No. Azure Virtual Desktop, VMware Horizon, Remote Desktop Services and kiosk builds are all tested the same way.
Can you test a kiosk or locked-down terminal?
Yes, and those engagements are usually short and productive.
Will you break anything on the host?
No. Escalation proof of concept is agreed in advance and nothing persists.
Do you go further into the domain?
Only as far as the scope allows. Many clients pair this with an internal network test for exactly that reason.
What if we use published browsers only?
Still testable. Browser escape through downloads, file dialogs and extensions is a standard part of this work.
What is included in the price?
Scoping, testing, the executive summary, the technical report, a walkthrough call and free retests until the finding is closed. One scope, one number, no follow-up invoices.
How fast can you start?
Scope to active testing in 24 hours once the scope is agreed, subject to tester availability in your window.
Are your testers CREST certified?
Yes. EJN Labs is a CREST member company and testing is delivered by CREST-qualified testers. The membership is verifiable on the CREST marketplace.
20+ CREST-accredited testing services in one place
Web, mobile, API, cloud, AI, infrastructure, red team. Pick the test that fits your environment.
Get your published desktops tested
Tell us what is published and to whom. You will have a fixed scope and a number within 24 hours.
