CVE-2011-1901
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 · uneditedThe mail-filter web interface in Proofpoint Messaging Security Gateway 6.2.0.263:6.2.0.237 and earlier in Proofpoint Protection Server 5.5.3, 5.5.4, 5.5.5, 6.0.2, 6.1.1, and 6.2.0 allows remote attackers to bypass authentication via unspecified vectors.
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 · moderate confidenceAuthentication bypass vulnerability in the mail-filter web interface of Proofpoint Messaging Security Gateway and Protection Server allows remote attackers to gain unauthorized access without credentials. The attack vector is unspecified in available documentation, affecting multiple versions across both product lines.
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<= 6.2.0.263\:6.2.0.237= 5.5.3= 5.5.4= 5.5.5= 6.0.2= 6.1.1= 6.2.0CVSS 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
- Partial
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:P/A:P
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 checksWork through these to decide whether this CVE applies to you.
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Identify if Proofpoint web interface is exposedCheck network accessibility of ports 443/8443 (HTTPS) or 80/8080 (HTTP) on the Proofpoint appliance. Use nmap or netstat to determine if the web interface is listening on external interfaces.Affected if The web interface is accessible from untrusted networks (internet-facing or less-trusted internal segments).
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Determine the installed product typeAccess the web interface login page and examine the login page source, error messages, or SSL certificate details. Alternatively, check the appliance's system information page or run 'pp_version' command via console/ssh if available.Affected if The product is either Proofpoint Messaging Security Gateway or Proofpoint Protection Server.
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Retrieve the exact version numberLog into the web interface as admin and navigate to Administration > System Information, or run 'pp_version' or 'grep version' from the command line on the appliance. Note the full version string.Affected if The installed version cannot be determined or is not visible (may indicate a non-standard installation).
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Compare version against affected rangesFor Messaging Security Gateway: check if version is <= 6.2.0.263 or <= 6.2.0.237 (the format suggests one of these). For Protection Server: check if version equals exactly 5.5.3, 5.5.4, 5.5.5, 6.0.2, 6.1.1, or 6.2.0.Affected if The installed version matches any of the affected versions listed in the CVE (any of the specific versions or within the range for Messaging Security Gateway).
If the Proofpoint web interface is exposed to untrusted networks and the installed version matches any of the affected versions (5.5.3, 5.5.4, 5.5.5, 6.0.2, 6.1.1, 6.2.0 for Protection Server; or <= 6.2.0.2xx for Messaging Security Gateway), the environment is likely vulnerable to this authentication bypass.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to patched versions as specified in vendor advisories. Until patched, restrict web interface access to trusted networks via firewall rules or VPN, and monitor for unauthorized access attempts.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-1901 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2011-1901 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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