Intrusion Prevention SystemApplication · Cisco
CVE-2011-4022
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 sensor in Cisco Intrusion Prevention System (IPS) 7.0 and 7.1 allows remote attackers to cause a denial of service (file-handle exhaustion and mainApp hang) by making authentication attempts that exceed the configured limit, aka Bug ID CSCto51204.
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 confidenceIn Cisco IPS 7.0 and 7.1, the sensor component does not properly limit authentication attempts, allowing remote attackers to exhaust file handles by sending excessive authentication requests beyond configured limits, causing the mainApp process to hang and resulting in denial of service.
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
Intrusion Prevention SystemApplication
= 7.0= 7.1CVSS 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
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/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 Cisco IPS sensor software versionUse the 'show version' or 'show module' command on the IPS sensor CLI to determine the installed sensor software versionAffected if The displayed version is 7.0 or 7.1 exactly
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Verify authentication rate limiting configurationAccess the IPS sensor CLI and locate the authentication settings or rate limiting configuration. Look for any configuration related to authentication attempt limits or login attempt thresholds.Affected if Authentication rate limiting is not explicitly configured, disabled, or set to allow unlimited attempts
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Check for file handle exhaustion indicatorsUse system diagnostic commands such as 'show processes' or 'show resources' to examine file descriptor/handle usage, or review system logs for file handle exhaustion warningsAffected if File handles are approaching exhaustion limits or abnormal consumption is observed
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Verify mainApp process stabilityExecute 'show process' or similar command to check the status of the mainApp process, and review recent logs for any process hang or restart eventsAffected if The mainApp process has hung, restarted unexpectedly, or shows instability
A defender is affected if their Cisco IPS sensor runs version 7.0 or 7.1 and authentication rate limiting is not properly enforced, leading to potential file handle exhaustion and mainApp process instability.
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 dataApply Cisco-provided patches for Bug ID CSCto51204 to address the authentication rate limiting deficiency, and review/adjust the configured authentication attempt limits if available.
Fix this in Intrusion Prevention System
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-4022 — 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-2011-4022 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
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