CVE-2020-24337
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 · uneditedAn issue was discovered in picoTCP and picoTCP-NG through 1.7.0. When an unsupported TCP option with zero length is provided in an incoming TCP packet, it is possible to cause a Denial-of-Service by achieving an infinite loop in the code that parses TCP options, aka tcp_parse_options() in pico_tcp.c.
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 confidencepicoTCP and picoTCP-NG through 1.7.0 contain a vulnerability in tcp_parse_options() in pico_tcp.c where an unsupported TCP option with zero length causes an infinite loop during parsing, leading to denial of service.
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<= 1.7.0<= 1.7.0CVSS 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
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 picoTCP installationSearch for picoTCP or picoTCP-NG files, libraries, or headers in the system (e.g., look for pico_tcp.c, pico_tcp.h, libpicotcp* files, or check build/system logs for picoTCP references)Affected if picoTCP or picoTCP-NG is present in the environment
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Determine the installed versionCheck version files, library version strings, or firmware/system documentation that references the picoTCP version; compare against the affected version 1.7.0Affected if The version is 1.7.0 or lower (for either picoTCP or picoTCP-NG)
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Verify TCP protocol support is enabledInspect the build configuration, Makefile, or runtime config to confirm TCP functionality is compiled in or enabled (look for TCP-related compile flags, modules, or config options)Affected if TCP protocol support is enabled in the picoTCP build
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Check for exposure to TCP trafficDetermine if the device/application using picoTCP processes incoming TCP connections or parses TCP packets from untrusted sourcesAffected if The system parses TCP options from network traffic (as the infinite loop occurs during tcp_parse_options() processing)
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Inspect tcp_parse_options source codeIf source code is available, examine pico_tcp.c for the tcp_parse_options function to verify whether proper bounds checking and exit conditions exist for zero-length options (the vulnerability exists if zero-length options can cause an infinite loop)Affected if The tcp_parse_options() function lacks proper handling for zero-length TCP options
You are affected if your environment uses picoTCP or picoTCP-NG version 1.7.0 or lower with TCP enabled and processes TCP traffic, since a zero-length TCP option in incoming packets will trigger an infinite loop in tcp_parse_options().
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 dataFix the tcp_parse_options() function to properly handle zero-length TCP options with appropriate bounds checking and exit conditions to prevent infinite loops.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-24337 — 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-2020-24337 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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