CVE-2020-20253Public exploitNetwork attack vector

Authenticated lcdstat crash via zero divisor

Published May 18, 2021 · Updated Aug 4, 2024

Divide-by-zero in MikroTik RouterOS before 6.47 allows remote authenticated users to crash the lcdstat process with a crafted packet. The packet drives the instruction at 0x08058539 to perform integer division with a zero-valued ECX register, raising SIGFPE. A valid RouterOS session is required, and the demonstrated consequence is an lcdstat process crash rather than code execution or data access.

CVSS severity6.5
Medium
EPSS probability2.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Divide-by-zero in MikroTik RouterOS before 6.47 allows remote authenticated users to crash the lcdstat process with a crafted packet. The packet drives the instruction at 0x08058539 to perform integer division with a zero-valued ECX register, raising SIGFPE. A valid RouterOS session is required, and the demonstrated consequence is an lcdstat process crash rather than code execution or data access.

The record

CVE
CVE-2020-20253
Published
May 18, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-369, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:N/A:P
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-369Divide By Zero
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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