CVE-2023-50432
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 · uneditedsimple-dhcp-server through ec976d2 allows remote attackers to cause a denial of service (daemon crash) by sending a DHCP packet without any option fields, which causes free_packet in dhcp_packet.c to dereference a NULL pointer.
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 confidencesimple-dhcp-server contains a NULL pointer dereference vulnerability in the free_packet function in dhcp_packet.c. When a DHCP packet arrives without any option fields, the function attempts to dereference a NULL pointer, causing the daemon to crash and resulting in a 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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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Check if simple-dhcp-server is installedRun 'dpkg -l simple-dhcp-server' on Debian-based systems or 'rpm -qa | grep simple-dhcp-server' on RHEL-based systems. Alternatively, check for the binary with 'which dhcpd' or 'ls /usr/sbin/dhcpd' and verify the package name matches simple-dhcp-server.Affected if The package is installed and matches the simple-dhcp-server product name.
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Identify the installed versionRun 'dpkg -s simple-dhcp-server' or 'rpm -qi simple-dhcp-server' to retrieve the version number. Compare this against any available version listings from your distribution or upstream release notes.Affected if No patched version is available from your distribution vendor, or the version predates the CVE disclosure date (December 2023).
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Verify the DHCP service is runningRun 'systemctl status dhcpd' or 'ps aux | grep dhcp' to check if the DHCP daemon process is active.Affected if The daemon is actively running and listening for DHCP requests.
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Confirm network exposure of the DHCP serviceCheck which interfaces the DHCP server binds to using 'netstat -tulpn | grep dhcp' or 'ss -tulpn | grep dhcp'. Review configuration in /etc/dhcp/dhcpd.conf or /etc/dhcpd.conf to see bind-address settings.Affected if The service is bound to a network interface accessible to untrusted clients, rather than loopback or a strictly isolated network.
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Inspect dhcp_packet.c for the vulnerable code patternIf source code is available, examine the free_packet function in dhcp_packet.c. Look for direct dereference of option field pointers without prior NULL validation, particularly before any packet->options or packet->field access.Affected if The source code shows free_packet accesses packet option fields without checking if options exist first (NULL pointer dereference vulnerability present).
You are affected if simple-dhcp-server is installed and running, the service is network-accessible to untrusted clients, and no patch has been applied to add NULL pointer validation in the free_packet function.
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 dataRestrict network access to the DHCP server to trusted clients until a patch is available. The fix requires adding proper NULL pointer validation in free_packet before dereferencing packet option fields.
- Consultation1.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-50432 — 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-2023-50432 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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