CVE-2020-36997Public exploit

Code execution via overlong imported text file

Published Jan 29, 2026 · Updated Jan 29, 2026

Stack-based buffer overflow in ksoft BacklinkSpeed 2.4 allows attackers to execute code by importing a crafted text file. The Import handler processes more than 5,000 bytes of file data without a length bound, overwriting the nSEH and SEH records on the stack. Attackers must induce a user to select the file through Import; control of the exception handler permits code execution with the application's privileges.

CVSS severity8.4
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in ksoft BacklinkSpeed 2.4 allows attackers to execute code by importing a crafted text file. The Import handler processes more than 5,000 bytes of file data without a length bound, overwriting the nSEH and SEH records on the stack. Attackers must induce a user to select the file through Import; control of the exception handler permits code execution with the application's privileges.

The record

CVE
CVE-2020-36997
Published
Jan 29, 2026
Updated
Jan 29, 2026
Vendor
ksoft
Product
BacklinkSpeed
Classifications
CWE-121, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

ksoft · BacklinkSpeedversion=2.4

Published CVSS scores

8.4VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1204.002User Execution: Malicious File

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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