CVE-2021-31895
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 has been identified in RUGGEDCOM i800 (All versions < V4.3.7), RUGGEDCOM i801 (All versions < V4.3.7), RUGGEDCOM i802 (All versions < V4.3.7), RUGGEDCOM i803 (All versions < V4.3.7), RUGGEDCOM M2100 (All versions < V4.3.7), RUGGEDCOM M2200 (All versions < V4.3.7), RUGGEDCOM M969 (All versions < V4.3.7), RUGGEDCOM RMC30 (All versions < V4.3.7), RUGGEDCOM RMC8388 V4.X (All versions < V4.3.7), RUGGEDCOM RMC8388 V5.X (All versions < V5.5.4), RUGGEDCOM RP110 (All versions < V4.3.7), RUGGEDCOM RS1600 (All versions < V4.3.7), RUGGEDCOM RS1600F (All versions < V4.3.7), RUGGEDCOM RS1600T (All versions < V4.3.7), RUGGEDCOM RS400 (All versions < V4.3.7), RUGGEDCOM RS401 (All versions < V4.3.7), RUGGEDCOM RS416 (All versions < V4.3.7), RUGGEDCOM RS416P (All versions < V4.3.7), RUGGEDCOM RS416Pv2 V4.X (All versions < V4.3.7), RUGGEDCOM RS416Pv2 V5.X (All versions < V5.5.4), RUGGEDCOM RS416v2 V4.X (All versions < V4.3.7), RUGGEDCOM RS416v2 V5.X (All versions < 5.5.4), RUGGEDCOM RS8000 (All versions < V4.3.7), RUGGEDCOM RS8000A (All versions < V4.3.7), RUGGEDCOM RS8000H (All versions < V4.3.7), RUGGEDCOM RS8000T (All versions < V4.3.7), RUGGEDCOM RS900 (32M) V4.X (All versions < V4.3.7), RUGGEDCOM RS900 (32M) V5.X (All versions < V5.5.4), RUGGEDCOM RS900G (All versions < V4.3.7), RUGGEDCOM RS900G (32M) V4.X (All versions < V4.3.7), RUGGEDCOM RS900G (32M) V5.X (All versions < V5.5.4), RUGGEDCOM RS900GP (All versions < V4.3.7), RUGGEDCOM RS900L (All versions < V4.3.7), RUGGEDCOM RS900W (All versions < V4.3.7), RUGGEDCOM RS910 (All versions < V4.3.7), RUGGEDCOM RS910L (All versions < V4.3.7), RUGGEDCOM RS910W (All versions < V4.3.7), RUGGEDCOM RS920L (All versions < V4.3.7), RUGGEDCOM RS920W (All versions < V4.3.7), RUGGEDCOM RS930L (All versions < V4.3.7), RUGGEDCOM RS930W (All versions < V4.3.7), RUGGEDCOM RS940G (All versions < V4.3.7), RUGGEDCOM RS969 (All versions < V4.3.7), RUGGEDCOM RSG2100 (All versions < V4.3.7), RUGGEDCOM RSG2100 (32M) V4.X (All versions < V4.3.7), RUGGEDCOM RSG2100 (32M) V5.X (All versions < V5.5.4), RUGGEDCOM RSG2100P (All versions < V4.3.7), RUGGEDCOM RSG2100P (32M) V4.X (All versions < V4.3.7), RUGGEDCOM RSG2100P (32M) V5.X (All versions < V5.5.4), RUGGEDCOM RSG2200 (All versions < V4.3.7), RUGGEDCOM RSG2288 V4.X (All versions < V4.3.7), RUGGEDCOM RSG2288 V5.X (All versions < V5.5.4), RUGGEDCOM RSG2300 V4.X (All versions < V4.3.7), RUGGEDCOM RSG2300 V5.X (All versions < V5.5.4), RUGGEDCOM RSG2300P V4.X (All versions < V4.3.7), RUGGEDCOM RSG2300P V5.X (All versions < V5.5.4), RUGGEDCOM RSG2488 V4.X (All versions < V4.3.7), RUGGEDCOM RSG2488 V5.X (All versions < V5.5.4), RUGGEDCOM RSG907R (All versions < V5.5.4), RUGGEDCOM RSG908C (All versions < V5.5.4), RUGGEDCOM RSG909R (All versions < V5.5.4), RUGGEDCOM RSG910C (All versions < V5.5.4), RUGGEDCOM RSG920P V4.X (All versions < V4.3.7), RUGGEDCOM RSG920P V5.X (All versions < V5.5.4), RUGGEDCOM RSL910 (All versions < V5.5.4), RUGGEDCOM RST2228 (All versions < V5.5.4), RUGGEDCOM RST2228P (All versions < V5.5.4), RUGGEDCOM RST916C (All versions < V5.5.4), RUGGEDCOM RST916P (All versions < V5.5.4). The DHCP client in affected devices fails to properly sanitize incoming DHCP packets. This could allow an unauthenticated remote attacker to cause memory to be overwritten, potentially allowing remote code execution.
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 confidenceThe DHCP client in RUGGEDCOM industrial networking devices fails to properly sanitize incoming DHCP packets. This vulnerability allows an unauthenticated remote attacker to cause memory corruption by sending specially crafted DHCP packets, potentially achieving remote code execution. The attack is network-adjacent (requiring the attacker to be on the same network segment to send DHCP responses) and does not require authentication.
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< 4.3.7< 4.3.7< 4.3.7< 4.3.7< 4.3.7< 4.3.7< 4.3.7< 4.3.7CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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 the RUGGEDCOM device modelAccess the device console or web interface and retrieve the exact model name (I800, I801, I802, I803, M969, M2100, M2200, or Rmc)Affected if The device model is any of these eight listed models
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Check the installed firmware versionAccess the device via console, CLI, or web interface and run the command to display firmware version (typically 'show version' or via the system information page)Affected if The firmware version is below 4.3.7 for V4.X devices (or below 5.5.4 for V5.X devices if applicable)
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Verify the DHCP client is enabledAccess the device configuration and check the DHCP client settings for the affected interface (typically 'show ip interface' or check the network configuration for DHCP client status)Affected if The DHCP client is enabled on any network interface
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Assess network exposure to untrusted DHCP responsesExamine the network topology and VLAN configuration to determine if the device is on a shared network segment where untrusted or malicious DHCP servers could respondAffected if The device is on a network segment where untrusted or unknown DHCP servers could inject crafted packets
A user is affected if they have one of the eight listed RUGGEDCOM models running firmware below 4.3.7 (or 5.5.4 for V5.X) with the DHCP client enabled on a network where untrusted DHCP responses can be received.
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 data4.3.7
Apply vendor-supplied firmware updates: upgrade to V4.3.7 or later for V4.X devices, and V5.5.4 or later for V5.X devices. As a compensating control, implement network segmentation to restrict DHCP traffic to trusted sources only.
- Consultation8.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-31895 — 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-2021-31895 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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