CVE-2025-20149
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 · uneditedA vulnerability in the CLI of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to a buffer overflow. An attacker with a low-privileged account could exploit this vulnerability by using crafted commands at the CLI prompt. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
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 confidenceA buffer overflow vulnerability in the CLI of Cisco IOS Software and Cisco IOS XE Software allows an authenticated local attacker with low-privilege account access to execute crafted commands that cause the affected device to reload unexpectedly, resulting in denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/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 the Cisco IOS or IOS XE versionRun 'show version' or 'show version | include Version' command on the device CLIAffected if The displayed version falls within Cisco's affected version ranges for CVE-2025-20149 (check Cisco's official advisory for specific version boundaries)
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Confirm the device runs IOS or IOS XEVerify the device output from 'show version' indicates Cisco IOS Software or Cisco IOS XE Software as the operating systemAffected if The device runs Cisco IOS or Cisco IOS XE software (this CVE does not apply to other Cisco operating systems)
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Check for local user accountsRun 'show users' or 'show running-config | include username' to list configured local accountsAffected if Local authentication is enabled and low-privilege user accounts exist on the device
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Verify console/VTY access is permittedRun 'show line' or check 'show running-config | include line' to see if VTY, console, or auxiliary lines are configured and activeAffected if Local CLI access is available to any authenticated user (exploitation requires only low-privilege local access)
The environment is affected if the device runs a vulnerable version of Cisco IOS or IOS XE and has local CLI authentication enabled for any user account, as the attacker only needs low-privilege local access to trigger the buffer overflow causing a reload.
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's official patches when available; limit and monitor CLI access to trusted users, as exploitation requires only a low-privilege local account.
- Consultation3.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-20149 — 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-2025-20149 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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