What is CVE-2021-42016?A high-severity flaw in Ruggedcom Ros, explained.

High severity1 affected product
The short answer

CVE-2021-42016 is a high-severity flaw (CVSS 7.5) in Ruggedcom Ros from Siemens, published on 8 March 2022. 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 0.6%. If you run an affected version, plan in the vendor’s fix.

Published 8 March 2022. Record last updated 12 August 2025. We keep this page's data up to date.

What it does

What is CVE-2021-42016? 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.

The official description

A vulnerability has been identified in RUGGEDCOM i800, RUGGEDCOM i801, RUGGEDCOM i802, RUGGEDCOM i803, RUGGEDCOM M2100, RUGGEDCOM M2100F, RUGGEDCOM M2200, RUGGEDCOM M2200F, RUGGEDCOM M969, RUGGEDCOM M969F, RUGGEDCOM RMC30, RUGGEDCOM RMC8388 V4.X, RUGGEDCOM RMC8388 V5.X, RUGGEDCOM RP110, RUGGEDCOM RS1600, RUGGEDCOM RS1600F, RUGGEDCOM RS1600T, RUGGEDCOM RS400, RUGGEDCOM RS400F, RUGGEDCOM RS401, RUGGEDCOM RS416, RUGGEDCOM RS416F, RUGGEDCOM RS416P, RUGGEDCOM RS416PF, RUGGEDCOM RS416Pv2 V4.X, RUGGEDCOM RS416Pv2 V5.X, RUGGEDCOM RS416v2 V4.X, RUGGEDCOM RS416v2 V5.X, RUGGEDCOM RS8000, RUGGEDCOM RS8000A, RUGGEDCOM RS8000H, RUGGEDCOM RS8000T, RUGGEDCOM RS900, RUGGEDCOM RS900 (32M) V4.X, RUGGEDCOM RS900 (32M) V5.X, RUGGEDCOM RS900F, RUGGEDCOM RS900G, RUGGEDCOM RS900G (32M) V4.X, RUGGEDCOM RS900G (32M) V5.X, RUGGEDCOM RS900GF, RUGGEDCOM RS900GP, RUGGEDCOM RS900GPF, RUGGEDCOM RS900L, RUGGEDCOM RS900M-GETS-C01, RUGGEDCOM RS900M-GETS-XX, RUGGEDCOM RS900M-STND-C01, RUGGEDCOM RS900M-STND-XX, RUGGEDCOM RS900W, RUGGEDCOM RS910, RUGGEDCOM RS910L, RUGGEDCOM RS910W, RUGGEDCOM RS920L, RUGGEDCOM RS920W, RUGGEDCOM RS930L, RUGGEDCOM RS930W, RUGGEDCOM RS940G, RUGGEDCOM RS940GF, RUGGEDCOM RS969, RUGGEDCOM RSG2100, RUGGEDCOM RSG2100 (32M) V4.X, RUGGEDCOM RSG2100 (32M) V5.X, RUGGEDCOM RSG2100F, RUGGEDCOM RSG2100P, RUGGEDCOM RSG2100P (32M) V4.X, RUGGEDCOM RSG2100P (32M) V5.X, RUGGEDCOM RSG2100PF, RUGGEDCOM RSG2200, RUGGEDCOM RSG2200F, RUGGEDCOM RSG2288 V4.X, RUGGEDCOM RSG2288 V5.X, RUGGEDCOM RSG2300 V4.X, RUGGEDCOM RSG2300 V5.X, RUGGEDCOM RSG2300F, RUGGEDCOM RSG2300P V4.X, RUGGEDCOM RSG2300P V5.X, RUGGEDCOM RSG2300PF, RUGGEDCOM RSG2488 V4.X, RUGGEDCOM RSG2488 V5.X, RUGGEDCOM RSG2488F, RUGGEDCOM RSG907R, RUGGEDCOM RSG908C, RUGGEDCOM RSG909R, RUGGEDCOM RSG910C, RUGGEDCOM RSG920P V4.X, RUGGEDCOM RSG920P V5.X, RUGGEDCOM RSL910, RUGGEDCOM RST2228, RUGGEDCOM RST2228P, RUGGEDCOM RST916C, RUGGEDCOM RST916P. A timing attack, in a third-party component, could make the retrieval of the private key possible, used for encryption of sensitive data.

If a threat actor were to exploit this, the data integrity and security could be compromised.

What kind of flaw is it?

  • CWE-203Observable Discrepancy
  • CWE-208Observable Timing Discrepancy
CVSS 3.1 scoreHigh · 7.5

How an attack on it works

Read straight from its severity rating, translated out of the shorthand.

  • Where an attacker can beAnywhere on the internet
  • How hard it is to pull offEasy: no special conditions
  • Login needed firstNo login needed
  • Does someone have to clickNo, nobody has to do anything
  • What an attacker getsCan read data

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

Exploitation

Is CVE-2021-42016 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 0.6%. That can change at any time, which is why we keep watching.

Known to be exploitedNoNot on the list of exploited flaws today
Chance of use in the next 30 days0.6%Its EPSS score, from the latest forecast

Timeline

  1. Published
  2. Record last updated
How Precursor Intelligence ranks it
46out of 100Medium

CVE-2021-42016 scores 46. Action: Plan remediation.

We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:

  • Evidence it is being exploitedBiggest factor
  • How severe it isStrong factor
  • How widely exposed it isSmaller factor
  • Threat activity around itSmaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.

When CVE-2021-42016 matches software you track, it lands in your list with its score and the reasons behind it.

See your own ranked list →
Affected products

Who is affected by CVE-2021-42016? One product.

The published record lists 1 product from 1 vendor. Versions are shown as published: "before 5.6.0" means every version up to, but not including, 5.6.0. If you run one of these, check your version, then go to the fix below.

Remediation

How do I fix CVE-2021-42016? Four steps.

  1. Check whether you run itCompare 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 fixInstall the update named in the vendor’s advisory. We’ve put the advisory first in the list.
  3. If you can’t patch todayFollow 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 itTrack 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.
Precursor Intelligence

Does CVE-2021-42016 affect you? We'll keep checking.

Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.

  1. Tell us what you runPick your software from a list, or let us work it out from your website.
  2. We match it to every flawOver 400,000 published flaws, checked against your list.
  3. Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
  4. Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.

Free plan, no card needed. Nothing to install.

FAQ

Common questions, answered plainly.

Something else? Talk to the team →

CVE-2021-42016 is a high-severity flaw in Ruggedcom Ros from Siemens, published on 8 March 2022. 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.

It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2021-42016 is 46 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.

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 0.6%. That can change at any time, which is why we keep watching.

For Ruggedcom Ros from Siemens: all versions, before 5.6.0.

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.