FreeBSDOperating system
CVE-2020-7461
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 · uneditedIn FreeBSD 12.1-STABLE before r365010, 11.4-STABLE before r365011, 12.1-RELEASE before p9, 11.4-RELEASE before p3, and 11.3-RELEASE before p13, dhclient(8) fails to handle certain malformed input related to handling of DHCP option 119 resulting a heap overflow. The heap overflow could in principle be exploited to achieve remote code execution. The affected process runs with reduced privileges in a Capsicum sandbox, limiting the immediate impact of an exploit.
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 confidenceFreeBSD's dhclient(8) contains a heap overflow vulnerability when handling malformed DHCP option 119 (Domain Search Option) input. This could potentially allow remote code execution, but the affected process runs with reduced privileges in a Capsicum sandbox, significantly limiting the immediate exploit impact.
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
FreeBSDOperating system
= 11.3= 11.4= 12.1all versionsall versionsCVSS 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
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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 FreeBSD versionRun `freebsd-version -k` or `uname -a` to determine the installed FreeBSD version and patch levelAffected if The version is 11.3, 11.4, or 12.1 without the respective patches (p13, p3, p9 or later)
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Identify running dhclient processRun `ps aux | grep dhclient` or check for active DHCP client leases in /var/db/ or /etc/dhclient.confAffected if A dhclient process is running and the system uses DHCP for network configuration
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Confirm DHCP is enabledCheck network interface configuration files in /etc/ or examine active network interfaces with `ifconfig` for DHCP-assigned addressesAffected if Any interface is configured to obtain IP addresses via DHCP, enabling dhclient
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Check for Siemens device firmware (if applicable)Access the device web interface or SNMP OID to retrieve firmware version informationAffected if The device is a Simatic Rf350m or Rf650m with any firmware version
A system is affected if it runs FreeBSD 11.3, 11.4, or 12.1 without the respective security patches AND uses dhclient for DHCP networking, or is a Siemens Simatic RF350m/RF650m device.
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 FreeBSD systems to patched versions: 12.1-RELEASE p9, 11.4-RELEASE p3, 11.3-RELEASE p13 or later, or stable branches after r365010/r365011.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation4.0 h
- Implementation4.0 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 $4,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-7461 — 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-2020-7461 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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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