/hunt-sharepoint

name: hunt-sharepoint
description: Hunt Microsoft SharePoint Server (2013/2016/2019/Subscription Edition) on-prem farms — anonymous endpoint enumeration, version disclosure, legacy SOAP login bypass (Authentication.asmx), ToolShell precondition chain (CVE-2025-53770), SafeControl reflection enumeration via Picker.aspx, NTLM Type-2 AD topology disclosure, custom-branding module discovery, EoL farm permanent-CVE-window exploitation, FormDigest anonymous issuance, file-extension blocklist NOT-an-oracle pattern, custom-zone Forms auth bridging on-prem AD. Use when target has SharePoint headers (SPRequestGuid, X-MS-InvokeApp, X-SharePointHealthScore, MicrosoftSharePointTeamServices) or paths (/_layouts/15/, /_vti_bin/, /_api/, /_catalogs/).
sources: github, authorized-engagement
report_count: 1

Crown Jewel Targets

SharePoint Server (on-prem) is one of the richest enterprise attack surfaces in 2025-2026 bug bounty / red-team work. Three forces converge:

1. **End-of-life unpatched code paths.** SharePoint Server 2013 reached extended-support EoL on 2023-04-11 (final build `15.0.5545.1000` / KB5002381). Every SharePoint CVE published after that date is **permanently unpatched** on SP2013 farms. SP2016 reaches EoL 2026-07-14; SP2019 reaches EoL 2026-07-14 (next 2 months as of May 2026); only SP Subscription Edition is currently in active support. 2. **CVE-2025-53770 / 53771 "ToolShell"** — July 2025 emergency-out-of-band patch chain for SPE / SP2019 / SP2016. The vulnerable code path (anonymous `/_layouts/15/ToolPane.aspx?DisplayMode=Edit` + anonymous `__REQUESTDIGEST` + unencrypted ViewState) is present in **SP2013 too** and will never receive a fix. 3. **Custom branded login pages forget legacy SOAP login.** `/_vti_bin/Authentication.asmx` with the `Login` SOAP op is the SharePoint equivalent of WordPress XMLRPC bypass — accepts native Forms credentials anonymously with no rate limit on most farms even when the branded UI has lockout.

**Highest-value SharePoint targets:**

• **SP2013 farms still on the public internet** — every CVE since April 2023 is unpatched. Critical-severity findings.
• **Dealer / partner / supplier portals** built on SharePoint by enterprise integrators (German VW group, a enterprise system integrator, etc.) — high-impact business data, often nested inside corporate AD trees.
• **SharePoint farms with anonymous Forms-auth zones** — Authentication.asmx becomes anonymously brute-forceable.
• **SharePoint inside corporate AD parent forests** — NTLM Type-2 leak (see `hunt-ntlm-info`) discloses the parent forest membership.
• **Telerik-integrated SharePoint installations** — additional deserialization sinks on top of SP's own.

**Asset types that pay most:** internet-reachable SP Server (any version) > SP Online with custom solutions hooks > intranet SP only after VPN compromise.

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Attack Surface Signals

**Response-header fingerprints (any one is sufficient — usually multiple co-occur):**

SPRequestGuid: <GUID>                           (always — anonymous and authenticated)
X-MS-InvokeApp: 1; RequireReadOnly              (SharePoint web request)
X-SharePointHealthScore: 0                      (SharePoint specific)
SPIisLatency: <ms>                              (SharePoint internal timing)
SPRequestDuration: <ms>                         (SharePoint request duration)
MicrosoftSharePointTeamServices: 15.0.0.0      (often stripped by ELB — but if present, exact version)
X-Forms_Based_Auth_Required: <login URL>        (Forms-auth zone indicator)
X-Forms_Based_Auth_Return_Url: <return URL>     (Forms-auth zone indicator)
X-MSDAVEXT_Error: 917656; Access denied...      (WebDAV extension active)
DAV: 1, 2                                       (WebDAV verbs supported)
Set-Cookie: ASP.NET_SessionId=...               (always — IIS session)
Set-Cookie: FedAuth=...; rtFa=...               (claims-mode auth)
Set-Cookie: WSS_FullScreenMode=...              (SharePoint UI mode)

**URL / path fingerprints:**

/_layouts/15/                  (SP2013+ layouts root — SP2010 used /_layouts/ without the 15)
/_layouts/14/                  (legacy SP2010 — almost EoL since 2020-10-13)
/_layouts/16/                  (some SP2019 / SPE)
/_vti_bin/                     (FrontPage-RPC + SOAP services)
/_vti_pvt/                     (FrontPage-RPC config — usually 403)
/_vti_inf.html                 (almost always anonymous; contains FPVersion banner)
/_api/                         (modern REST API)
/_api/$metadata                (OData metadata — often anonymous + large)
/_api/contextinfo              (FormDigest issuer — POST only)
/_catalogs/                    (site catalogs: masterpage, wp, lt, theme, solutions)
/_catalogs/users/simple.aspx   (user list — usually 403)
/_layouts/15/start.aspx        (anonymous landing — leaks version)
/_layouts/15/ToolPane.aspx     (web part editor — ToolShell sink)
/_layouts/15/Picker.aspx       (people/list picker — SafeControl recon)
/_layouts/15/download.aspx     (SP-internal file resolver — NOT outbound SSRF)
/_layouts/15/Authenticate.aspx (forms-auth redirector)
/_layouts/15/SignOut.aspx      (logout)
/_layouts/15/error.aspx        (error page — anonymous)
/_layouts/15/AccessDenied.aspx (denied page — anonymous)
/_layouts/15/scriptresx.ashx?culture=en-us&name=core    (resource bundle leak)
/_layouts/15/<Customer>/       (custom-branding modules — see Methodology step 8)
/_vti_bin/Authentication.asmx  (THE legacy login bypass — see hunt-auth-bypass Legacy-Protocol Matrix)
/_vti_bin/SharedAccess.asmx    (often anon-readable)
/_vti_bin/lists.asmx           (auth-required on hardened farms)
/_vti_bin/sites.asmx           (auth-required on hardened farms)
/_vti_bin/sts/                 (Security Token Service — usually 302 to error)
/sites/<name>/                 (site collections)
/personal/<user>/              (MySite / OneDrive-for-Business)

**Body signals (in HTML responses):**

<meta name="GENERATOR" content="Microsoft Sh