SharePoint Penetration Testing
SharePoint penetration testing for where the documents are, which makes permission inheritance and sharing links a data protection issue rather than a configuration detail. Anyone links need no sign-in and cannot be audited. CREST-certified testers, fixed price from £2,840 for a 2-day single-platform scope, quoted within 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.”
“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.”
SharePoint permissions start simple and drift. A library breaks inheritance for one project, a site owner grants a group access for a deadline, a sharing link goes to a personal address and never expires. After a few years no one can answer the question the auditor asks: who can read this?
Why sharing settings decide who can read what
The failure modes are specific and repeatable. The default sharing link set to Anyone. Everyone except external users granted on a site. Inheritance broken on one library and never restored. External sharing left at Anyone for the whole organisation. Site owners inviting guests who are never removed.
External sharing is turned on by default for your organisation, and an Anyone link needs no sign-in and its use cannot be audited. Everyone except external users is a built-in group holding every internal account, so one grant on a site opens it to the whole company. The link types are set out in Sharing and permissions in the SharePoint modern experience.
We test it as an ordinary signed-in user and as a guest, trying to open libraries, search results and sharing links across sites we were never invited to. Each route in is recorded as a path. On-premises farms also get version, patch level and service account checks. ISO 27001, SOC 2, PCI DSS and Cyber Essentials Plus audits accept manual penetration test evidence. Scan-only evidence is generally insufficient.
SHAREPOINT SPECIFICS
What We Actually Test in a SharePoint Environment
Ten areas that apply because the platform is SharePoint, whether on-premises or online, on top of the standard application checks. Every finding is verified, reproducible and mapped to CWE and CVSS 3.1.
Version and exposure
On-premises version and patch level, internet exposure, and the known issues that apply to the build.
Permission inheritance
Sites, libraries and lists where inheritance is broken, and who gained access as a result.
Enumeration as a standard user
What a normal account can discover and open across the tenant or farm, including sites it was never meant to see.
Sharing links
Anonymous and organisation-wide links, expiry, and links to content that should never have left its site.
External and guest access
Guest accounts, external sharing policy, and what a guest reaches beyond the site they were invited to.
Custom web parts and solutions
Custom code, SPFx solutions and scripts, and the permissions they run with.
Power Platform connections
Power Automate flows and Power Apps that read or write SharePoint data, and the connections they use.
Search exposure
What search surfaces to an ordinary user, including content in sites they cannot browse to directly.
Service accounts and farm security
On-premises service accounts, their rights in the domain, and the path from the web front end inwards.
Audit and retention
Audit log coverage, retention labels, versioning and recycle bin behaviour for sensitive content.
METHODOLOGY
What a SharePoint 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.
Spoofed authentication token grants administrator access without credentials
- Affected
- An on-premises SharePoint Server farm at [redacted], reachable from the corporate network and from the VPN.
- What we found
- The farm accepted a spoofed authentication token, which gave us administrator privileges with no password and no multi-factor prompt. Site collections holding HR and legal documents were readable from that context.
- Why it matters
- Administrative access to every site collection on the farm from an unauthenticated position, including document libraries the business assumed were restricted by permission.
- Fix
- Apply the security update, enable antimalware scan interface integration for SharePoint, rotate the farm and service account credentials, and review document access logs for the whole exposure window.
Reconstructed from public research: CVE-2023-29357, Microsoft SharePoint Server elevation of privilege, CVSS 3.1 base score 9.8.
SharePoint 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 SharePoint 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 £2,840 for a small, single-scope engagement, agreed up front. Most engagements run £4,390 and up. No day-rate surprises.
Dan WilcocksonFounder, 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.
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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 SharePoint Penetration Testing Pricing
Pricing depends on app complexity, user-role count, business-logic depth, and integration surface. The day count flexes; the included deliverables stay the same across all engagements.
2 to 4 testing days
Single user role, basic CRUD application, marketing website with auth. Around 5 working days from kickoff to report.
Get a fixed quote4 to 5 testing days
Multi-role SaaS, business application with payment integration. Around 8 to 12 working days from kickoff to report.
Get a fixed quote5 to 7 testing days
Multi-tenant platform, complex authorisation matrix, integration-heavy applications. Around 15 to 20 working days from kickoff to report.
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
SharePoint 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 SharePoint 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
Online, on-premises, or both?
Either. The permission work is the same, and on-premises adds the server and service account testing.
Is this the same as your Microsoft 365 review?
They overlap. The 365 review covers the tenant broadly. This goes deep on SharePoint permissions and content.
What access do you need?
One standard user account. A read-only administrative view makes the permission mapping much more complete.
Will you open our confidential documents?
We confirm access and record the path. Contents are not copied, and anything quoted is redacted.
Do you cover OneDrive too?
Yes. It is the same permission and sharing model applied to personal storage.
Can you tell us what to fix first?
Findings are ordered by what is reachable by whom, so the remediation order follows the exposure.
Our default sharing link is set to Anyone. Is that a problem?
It can be. The default link type decides which option users are offered first, and an Anyone link works without sign-in with no way to audit who used it. We check which libraries hand out Anyone links, whether they expire, and whether they carry edit rights.
Everyone except external users is on one of our sites. Is that a problem?
It is if the site holds anything that should not be company-wide. That built-in group automatically includes all internal users and excludes guests, so one grant opens the site to every member of staff. We sign in as an ordinary account, open the site, and list what else the group reaches.
Our SharePoint search shows files we did not mean people to find. Is that a permissions problem?
The fix is the permission. Restricted Content Discovery can hide a site from organisation-wide search and Copilot while owners review it, but it does not change existing permissions, so users with access can still open the files. We search as a standard user, open every result, and trace each one back to the grant that allowed it.
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Find out who can actually read what
Tell us whether it is online, on-premises or both. You will have a fixed scope and a number within 24 hours.
