Ios XeOperating system · Cisco
CVE-2020-3513
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 · uneditedMultiple vulnerabilities in the initialization routines that are executed during bootup of Cisco IOS XE Software for Cisco ASR 900 Series Aggregation Services Routers with a Route Switch Processor 3 (RSP3) installed could allow an authenticated, local attacker with high privileges to execute persistent code at bootup and break the chain of trust. These vulnerabilities are due to incorrect validations by boot scripts when specific ROM monitor (ROMMON) variables are set. An attacker could exploit these vulnerabilities by copying a specific file to the local file system of an affected device and defining specific ROMMON variables. A successful exploit could allow the attacker to run arbitrary code on the underlying operating system (OS) with root privileges. To exploit these vulnerabilities, an attacker would need to have access to the root shell on the device or have physical access to the device.
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 confidenceVulnerability in Cisco IOS XE bootup validation routines for ASR 900 Series routers with RSP3 module. Attackers with root shell or physical access can copy a specific file to local storage and set ROMMON variables to bypass boot script validation, executing arbitrary code with root privileges at device bootup.
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
Ios XeOperating system
= 16.12.1= 17.2CVSS 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
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
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 device model and hardware moduleRun 'show version' or 'show platform' to confirm the device is an ASR 900 Series router with an RSP3 module installedAffected if The device is an ASR 900 Series with RSP3 module - other models/modules are not affected by this specific vulnerability
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Check installed IOS XE versionRun 'show version' and locate the IOS XE software version string (for example, 16.12.1, 17.2.x)Affected if The version is 16.12.1 or 17.2 (any subversion within these releases) - versions outside this range are not affected
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Verify root shell accessibilityCheck if root shell or privileged access is available through user accounts, management interfaces, or out-of-band access methodsAffected if Root shell access is available to any user - this is required for one attack vector in this CVE
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Assess physical access exposureReview physical security controls and access logs for the device location to determine if unauthorized physical access is possibleAffected if Physical access to the device is not fully restricted - this is required for the other attack vector in this CVE
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Inspect local storage for suspicious filesExamine the device's local storage (flash, bootflash) for any unexpected or unknown files that could be the specific file referenced in the attackAffected if Unknown files exist in local storage that were not placed by legitimate administration workflows
The device is affected if it is an ASR 900 Series with RSP3 module running IOS XE version 16.12.1 or 17.2 AND either root shell is accessible or physical access to the device is possible.
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 IOS XE software updates addressing this vulnerability; restrict physical access to devices and limit root shell availability to reduce attack surface.
Fix this in Ios Xe
Scoped from the published advisory
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 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 $4,304.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3513 — 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-2020-3513 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
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