CVE-2023-51847
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 in obgm and Libcoap v.a3ed466 allows a remote attacker to cause a denial of service via thecoap_context_t function in the src/coap_threadsafe.c:297:3 component.
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 confidenceA denial of service vulnerability exists in the coap_context_t function within the thread-safe handling code (coap_threadsafe.c:297) of the Libcoap library. A remote attacker can trigger this to cause a DoS condition.
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
- 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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Detect if Libcoap is installedSearch for libcoap library files on the system (e.g., locate libcoap, dpkg -l | grep coap, rpm -qa | grep coap, or check for coap-related binaries in /usr/bin or /usr/sbin)Affected if Libcoap library files or coap-related binaries are found on the system
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Identify Libcoap versionRun coap-client --version or check package manager for libcoap version (dpkg -s libcoap-1 or similar), or inspect the shared library version if foundAffected if The installed version matches or predates any unpatched release of Libcoap containing the thread-safe handling code in coap_threadsafe.c
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Verify CoAP service is network-exposedCheck listening ports for UDP/TCP ports 5683 (default CoAP) or custom ports; review firewall rules and network configurations for coap-server or coap-daemon servicesAffected if A CoAP service using Libcoap is listening on a network-accessible port
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Confirm thread-safe mode is enabledInspect the CoAP server or application configuration for thread-safe options, or review the application code that initializes coap_context_t for thread-safe initialization flagsAffected if The CoAP application is configured to use or depends on the thread-safe handling code path in Libcoap
A user is affected if they are running a vulnerable, unpatched version of Libcoap with an exposed CoAP service that utilizes the thread-safe handling functionality.
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 dataUpdate to a patched version of Libcoap if available; otherwise, review and restrict network exposure to CoAP endpoints using this library.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 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 $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-51847 — 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-2023-51847 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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