Session Cookie Missing 'HttpOnly' Flag
This session cookie is readable by JavaScript, so any script that runs on your page can steal it — including one injected through a cross-site scripting bug.
Why it matters
This session cookie is readable by JavaScript, so any script that runs on your page can steal it — including one injected through a cross-site scripting bug. HttpOnly is what stops an XSS bug from becoming a permanent account takeover.
How ShipReady detects it
Inspects Set-Cookie on responses the scan already fetched. Only cookies whose name suggests a session — containing session, token, auth, sid, jwt, user or login — are examined. A preference or analytics cookie missing HttpOnly is not a finding worth anyone's attention, and flagging it would bury the one that matters. Flags are parsed from the raw header rather than a cookie library, because valueless attributes are dropped by some parsers and their absence is exactly what this check exists to detect. Runs on every crawled page, which is what makes it useful: a logged-out homepage usually sets nothing at all, while /login sets the cookie whose flags actually matter.
Detection is deterministic. ShipReady reports this only when it observes the condition directly, and prefers to miss a real problem over inventing one. Rule version 1.2.0.
How to fix it
This is the prompt ShipReady puts in your report — written to be pasted straight into Cursor, Claude Code, or whichever assistant built the app.
The '{cookie_name}' session cookie is missing the 'HttpOnly' flag. This makes the cookie accessible via JavaScript, exposing it to XSS attacks. Add the HttpOnly flag.Frequently asked questions
- What does "Session Cookie Missing 'HttpOnly' Flag" mean?
- This session cookie is readable by JavaScript, so any script that runs on your page can steal it — including one injected through a cross-site scripting bug.
- How serious is it?
- ShipReady rates this high. Fix before launch. A real weakness that an attacker can act on.
- How do I fix it?
- Paste the fix prompt on this page into Cursor, Claude Code or your AI editor. It is the same prompt ShipReady puts in your report.
- Can I check my own site?
- Yes — ShipReady scans up to ten pages of any public site for free and reports this alongside every other check.
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