# What is CVE-2021-31895?

> CVE-2021-31895 is a high-severity flaw (CVSS 8.1) in Ruggedcom Ros I800 from Siemens, published on 13 July 2021. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 2.2%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2021-31895

## At a glance

- **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle.
- **Precursor Intelligence risk score:** 55 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 8.1 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 2.2% (latest exploit-likelihood forecast)
- **Published:** 13 July 2021
- **Record last updated:** 14 October 2025
- **Main product:** Ruggedcom Ros I800 from Siemens
- **Affected products:** 52

## What is CVE-2021-31895? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### The official description

A 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.

### What kind of flaw is it?

- CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
- CWE-787: Out-of-bounds Write

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Hard: conditions must line up
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data, change data and take it offline

Severity vector: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Is CVE-2021-31895 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.2%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 2.2%, 2.2%, 2.2%, 2.2%, 2.2%, 2.2%, 2.2%.

### Timeline

- 13 July 2021: Published
- 14 October 2025: Record last updated

### How Precursor Intelligence ranks it

CVE-2021-31895 scores **55 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2021-31895?

The published record lists 52 products. Versions are as published: "before 4.3.7" means every version up to, but not including, 4.3.7.

- [Ruggedcom Ros I800](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_i800) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rmc8388](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rmc8388) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rs416v2](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs416v2) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.5.0 to before 5.5.4
- [Ruggedcom Ros Rs900](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs900) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rs900g](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs900g) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rsg2100](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2100) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rsg2100p](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2100p) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.3.4
- [Ruggedcom Ros Rsg2288](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2288) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rsg2300](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2300) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.3.4
- [Ruggedcom Ros Rsg2300p](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2300p) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.5.0 to before 5.5.4
- [Ruggedcom Ros Rsg2488](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2488) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rsg900](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg900) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.5.0 to before 5.5.4
- [Ruggedcom Ros Rsg900g](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg900g) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros Rsg920p](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg920p) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7, 5.0.0 to before 5.5.4
- [Ruggedcom Ros I801](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_i801) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros I802](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_i802) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros I803](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_i803) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros M2100](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_m2100) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros M2200](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_m2200) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros M969](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_m969) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rmc](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rmc) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rmc20](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rmc20) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rmc30](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rmc30) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rmc40](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rmc40) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rmc41](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rmc41) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rp110](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rp110) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs400](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs400) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs401](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs401) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs416](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs416) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs8000](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs8000) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs8000a](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs8000a) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs8000h](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs8000h) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs8000t](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs8000t) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs900gp](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs900gp) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs900l](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs900l) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs900w](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs900w) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs910](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs910) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs910l](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs910l) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs910w](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs910w) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs920l](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs920l) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs920w](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs920w) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs930l](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs930l) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs930w](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs930w) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs940g](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs940g) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rs969](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rs969) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rsg2200](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg2200) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 4.3.7
- [Ruggedcom Ros Rsg900c](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg900c) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 5.5.4
- [Ruggedcom Ros Rsg900r](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsg900r) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 5.5.4
- [Ruggedcom Ros Rsl910](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rsl910) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 5.5.4
- [Ruggedcom Ros Rst2228](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rst2228) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 5.5.4
- [Ruggedcom Ros Rst916c](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rst916c) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 5.5.4
- [Ruggedcom Ros Rst916p](https://www.precursorintelligence.com/product/siemens/ruggedcom_ros_rst916p) by [Siemens](https://www.precursorintelligence.com/vendors/siemens) (Operating system): before 5.5.4

## How do I fix CVE-2021-31895?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [cert-portal.siemens.com](https://cert-portal.siemens.com/productcert/pdf/ssa-373591.pdf) (Vendor advisory)
- [cert-portal.siemens.com](https://cert-portal.siemens.com/productcert/html/ssa-373591.html)

## Questions

### What is CVE-2021-31895?

CVE-2021-31895 is a high-severity flaw in Ruggedcom Ros I800 from Siemens, published on 13 July 2021. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### How serious is CVE-2021-31895?

It scores 8.1 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2021-31895 is 55 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2021-31895 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.2%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2021-31895 affect?

For Ruggedcom Ros I800 from Siemens: before 4.3.7. The record lists 52 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2021-31895?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2021-31895 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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