iOSOperating system · Cisco
CVE-2005-1057
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 · uneditedCisco IOS 12.2T, 12.3 and 12.3T, when using Easy VPN Server XAUTH version 6 authentication, allows remote attackers to bypass authentication via a "malformed packet."
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 confidenceThis is an authentication bypass vulnerability in Cisco IOS Easy VPN Server's XAUTH version 6 implementation. Remote attackers can bypass the XAUTH authentication mechanism by sending a specifically crafted 'malformed packet,' potentially gaining unauthorized VPN access without valid credentials.
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
iOSOperating system
= 12.2t= 12.3= 12.3tCVSS 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 the Cisco IOS versionUse the 'show version' command on the Cisco device to display the installed iOS version number and trainAffected if The displayed version matches exactly 12.2t, 12.3, or 12.3t (or falls within these specific trains)
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Confirm Easy VPN Server is configuredUse 'show running-config | include crypto isakmp' and 'show running-config | include xauth' to check for IPSec VPN and XAUTH configuration linesAffected if Crypto ISAKMP and XAUTH configuration commands are present in the running configuration
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Check for IPSec VPN profile bindingUse 'show running-config | include crypto map' to display crypto map entries, and verify if Easy VPN Server profiles (often named 'profile' or 'ra-manual') are applied to interfacesAffected if Crypto map entries referencing VPN profiles are applied to at least one interface (typically an outside or WAN interface)
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Verify XAUTH is enabled in the IPSec profileUse 'show crypto isakmp profile' to list configured ISAKMP profiles and confirm XAUTH is listed as an authentication method within themAffected if ISAKMP profiles exist and show XAUTH as an active authentication mechanism
A device is affected if it runs exactly iOS 12.2t, 12.3, or 12.3t AND has Easy VPN Server with XAUTH authentication enabled and applied to an interface.
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 Cisco IOS to a version that addresses this vulnerability (consult Cisco's IOS upgrade paths and release notes). If immediate patching is not feasible, implement network-level access controls to limit VPN exposure to trusted networks.
Fix this in iOS
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2005-1057 — 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-2005-1057 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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- Version or environment caveats, and links to real fixes
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