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Adaptive Security Appliance SoftwareOperating system · Cisco

CVE-2011-3303

HIGH · 7.8 CVSS v2.0 Published 2011-10-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
87/100
Remediation priority · High
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
Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services module in Cisco Catalyst 6500 series devices, with software 7.0 before 7.0(8.13), 7.1 and 7.2 before 7.2(5.4), 8.0 before 8.0(5.25), 8.1 before 8.1(2.50), 8.2 before 8.2(5.6), 8.3 before 8.3(2.23), 8.4 before 8.4(2.7), and 8.5 before 8.5(1.1) and Cisco Firewall Services Module (aka FWSM) 3.1 before 3.1(21), 3.2 before 3.2(22), 4.0 before 4.0(16), and 4.1 before 4.1(7) allow remote attackers to cause a denial of service (device reload) via malformed ILS traffic, aka Bug IDs CSCtq57697 and CSCtq57802.

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

Denial of service vulnerability in Cisco ASA 5500 series, ASA Services module in Catalyst 6500, and Cisco Firewall Services Module (FWSM). Malformed ILS (Internet Locator Service) traffic can trigger a device reload, causing network disruption. The vulnerability affects multiple software version branches from 7.x through 8.x.

MitigationApply Cisco-supplied software patches for affected versions: ASA 7.0(8.13), 7.2(5.4), 8.0(5.25), 8.1(2.50), 8.2(5.6), 8.3(2.23), 8.4(2.7), 8.5(1.1) and later; FWSM 3.1(21), 3.2(22), 4.0(16), 4.1(7) and later.

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
Adaptive Security Appliance SoftwareOperating system
Affected:= 7.0= 7.0\(0\)= 7.0\(1\)= 7.0\(2\)= 7.0\(4\)= 7.0\(5\)= 7.0\(5.2\)= 7.0\(6\)= 7.0\(6.7\)= 7.0\(7\)= 7.0\(8\)= 7.0.1
5500 Series Adaptive Security ApplianceHardware / appliance
Affected:all versions
Asa 5500Hardware / appliance
Affected:all versions
Firewall Services Module SoftwarePlugin / extension
Affected:= 3.1= 3.1\(2\)= 3.1\(3\)= 3.1\(4\)= 3.1\(5\)= 3.1\(6\)= 3.1\(7\)= 3.1\(8\)= 3.1\(9\)= 3.1\(10\)= 3.1\(11\)= 3.1\(12\)
Catalyst 6500Hardware / appliance
Affected:all versions
Catalyst 7600Hardware / appliance
Affected:all versions

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
None
Integrity
None
Availability
Complete

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

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. Identify the device model
    Run 'show version' or 'show inventory' to confirm the hardware model. Look for ASA 5500 series, Catalyst 6500, or Catalyst 7600 chassis with FWSM module.
    Affected if Device is not one of the affected models (ASA 5500, ASA Services module in Catalyst 6500, or FWSM)
  2. Determine the ASA software version
    Run 'show version' and locate the 'Cisco Adaptive Security Appliance Software' version line. Compare against affected 7.x and 8.x branches.
    Affected if Version starts with 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, or 8.8 (for ASA Software)
  3. Determine the FWSM software version
    If using FWSM module, run 'show module' and 'show version' from the switch. Compare against affected 3.1.x versions listed.
    Affected if FWSM version is 3.1.x (specifically 3.1 through 3.1(12))
  4. Check if ILS inspection is enabled
    Run 'show service-policy inspect ils' or examine the configuration with 'show run | include inspect ils' to see if ILS protocol inspection is configured.
    Affected if ILS inspection is enabled and the device is running an affected software version

Device is affected if it is an ASA 5500, ASA Services module in Catalyst 6500, or FWSM running an affected 7.x/8.x software version AND ILS inspection is enabled, allowing malformed ILS traffic to trigger a reload.

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

Apply Cisco-supplied software patches for affected versions: ASA 7.0(8.13), 7.2(5.4), 8.0(5.25), 8.1(2.50), 8.2(5.6), 8.3(2.23), 8.4(2.7), 8.5(1.1) and later; FWSM 3.1(21), 3.2(22), 4.0(16), 4.1(7) and later.

Fix this in Adaptive Security Appliance Software Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2011-3303 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