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iOSOperating system · Cisco

CVE-2009-0637

HIGH · 7.1 CVSS v2.0 Published 2009-03-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
Remotely reachable 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
The SCP server in Cisco IOS 12.2 through 12.4, when Role-Based CLI Access is enabled, does not enforce the CLI view configuration for file transfers, which allows remote authenticated users with an attached CLI view to (1) read or (2) overwrite arbitrary files via an SCP command.

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 confidence

The SCP server in Cisco IOS 12.2-12.4 fails to enforce Role-Based CLI Access (RBAC) view restrictions during file transfer operations, allowing authenticated users with assigned CLI views to bypass authorization and read or write to arbitrary files on the device through SCP protocol.

MitigationUpgrade to a patched Cisco IOS version beyond 12.4, or disable the SCP server if not required, and verify RBAC view restrictions are properly enforced for file operations.

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
Affected:= 12.2= 12.2b= 12.2bc= 12.2bw= 12.2bx= 12.2by= 12.2bz= 12.2ca= 12.2cx= 12.2cy= 12.2cz= 12.2da
Ios XrOperating system
Affected:= 12.4

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
High
Authentication
Single
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:H/Au:S/C:C/I:C/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. Check the Cisco IOS/IOS XR version
    Execute 'show version' and look for version 12.2 (any subversion) or version 12.4
    Affected if The version matches 12.2 (any of the listed subversions: b, bc, bw, bx, by, bz, ca, cx, cy, cz, da) or version 12.4 exactly
  2. Verify SCP server is enabled
    Execute 'show ip ssh' or 'show running-config | include ip scp' to see if SCP server is configured
    Affected if SCP server is enabled on the device
  3. Confirm RBAC views are configured
    Execute 'show view' or check configuration for 'parser view' commands
    Affected if One or more RBAC views exist in the configuration
  4. Identify users with assigned CLI views
    Execute 'show users' and check for users with view assignments, or review configuration for 'username <user> view <viewname>'
    Affected if There are users authenticated with assigned CLI views

All four conditions must be present: affected IOS version (12.2 or 12.4), SCP server enabled, RBAC views configured, and users with assigned CLI views - if all are true, the environment is vulnerable to authorization bypass via SCP file transfers.

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

Upgrade to a patched Cisco IOS version beyond 12.4, or disable the SCP server if not required, and verify RBAC view restrictions are properly enforced for file operations.

Fix this in iOS Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2009-0637 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
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