Parallels Plesk Small Business PanelApplication · Parallels

CVE-2011-4756

MEDIUM · 5.0 CVSS v2.0 Published 2011-12-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Parallels Plesk Small Business Panel 10.2.0 does not include the HTTPOnly flag in a Set-Cookie header for a cookie, which makes it easier for remote attackers to obtain potentially sensitive information via script access to this cookie, as demonstrated by cookies used by domains/sitebuilder_edit.php and certain other files.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Parallels Plesk Small Business Panel 10.2.0 fails to set the HTTPOnly flag on session cookies in Set-Cookie headers. Without this flag, cookies are accessible via JavaScript, allowing attackers to steal session identifiers through cross-site scripting (XSS) vulnerabilities.

MitigationAdd the HTTPOnly attribute to all Set-Cookie headers, particularly in domains/sitebuilder_edit.php and related authentication handlers. Upgrade to a patched version if available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Parallels Plesk Small Business PanelApplication
Affected:= 10.2.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None

AV:N/AC:L/Au:N/C:P/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Parallels Plesk Small Business Panel version
    Locate the Plesk installation and determine the exact version number. On Linux servers, check /usr/local/psa/version or use the plesk version command. On Windows, check the registry or Plesk control panel about page.
    Affected if The installed version is exactly 10.2.0 (the only version listed as affected for this CVE).
  2. Identify session cookies from Plesk
    Log into the Plesk control panel and use browser developer tools (F12) or a proxy tool to capture HTTP responses. Look for Set-Cookie headers during login and authentication processes.
    Affected if Session cookies are present in the response headers.
  3. Inspect Set-Cookie headers for HTTPOnly flag
    Examine each Set-Cookie header returned by Plesk authentication endpoints. Check if the HttpOnly attribute is present in the cookie definition.
    Affected if The Set-Cookie header does NOT contain the HttpOnly attribute (case-insensitive), meaning the cookie can be accessed via JavaScript.
  4. Verify cookie accessibility via JavaScript
    If possible, access the Plesk control panel and use browser console to execute document.cookie and verify if session identifiers are exposed.
    Affected if Session cookie values appear in document.cookie output, confirming they are accessible to JavaScript and the HTTPOnly flag is missing.

The environment is affected if running Parallels Plesk Small Business Panel exactly version 10.2.0 and session cookies lack the HttpOnly attribute in their Set-Cookie headers, allowing XSS-based session theft.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Add the HTTPOnly attribute to all Set-Cookie headers, particularly in domains/sitebuilder_edit.php and related authentication handlers. Upgrade to a patched version if available.

Fix this in Parallels Plesk Small Business Panel Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,000
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2011-4756 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data