StarosOperating system · Cisco
CVE-2020-3244
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 Enhanced Charging Service (ECS) functionality of Cisco ASR 5000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass the traffic classification rules on an affected device. The vulnerability is due to insufficient input validation of user traffic going through an affected device. An attacker could exploit this vulnerability by sending a malformed HTTP request to an affected device. A successful exploit could allow the attacker to bypass the traffic classification rules and potentially avoid being charged for traffic consumption.
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 confidenceThis is an input validation vulnerability in the Enhanced Charging Service (ECS) of Cisco ASR 5000 Series routers. An unauthenticated remote attacker can send malformed HTTP requests to bypass traffic classification rules, allowing them to avoid being charged for data consumption. The root cause is insufficient validation of user traffic passing through the device.
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
StarosOperating system
< 21.18.0CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
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 device modelLog into the router CLI and run 'show hardware' or 'show version' to confirm this is a Cisco ASR 5000 Series routerAffected if Device is a Cisco ASR 5000 Series router running Cisco Staros
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Check the Cisco Staros versionRun 'show version' or 'show build' in the router CLI to retrieve the installed Staros version numberAffected if Installed Staros version is lower than 21.18.0 (for example, 21.17.0, 21.16.0, etc.)
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Verify Enhanced Charging Service is enabledRun 'show configuration ecs' or 'show ecs status' in the CLI to check if ECS feature is actively configured on the deviceAffected if ECS is enabled and actively processing traffic classification rules
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Inspect ECS classification rules for HTTPRun 'show ecs policy' or 'show ecs charging-rule' to view the defined traffic classification rules, particularly those handling HTTP trafficAffected if There are active HTTP charging/classification rules that could be bypassed
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Review traffic logs for malformed HTTP requestsCheck ECS billing or accounting logs using 'show logs billing' or 'show logs charging' for unusual HTTP request patterns that may indicate rule bypass attemptsAffected if Logs show HTTP traffic that is not being classified or charged as expected based on configured rules
The environment is affected if it is a Cisco ASR 5000 Series router running Cisco Staros version below 21.18.0 with ECS enabled and processing HTTP traffic classification rules.
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 data21.18.0
Apply the Cisco vendor patch/softwre update for CVE-2020-3244. If unavailable, implement additional monitoring for anomalous HTTP traffic patterns that may indicate exploitation and consider network-level controls to validate traffic classification.
Fix this in Staros
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-2020-3244 — 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-2020-3244 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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