CVE-2025-57623Public exploitNetwork attack vector

Unauthenticated service crash via empty JSON body

Published Sep 25, 2025 · Updated Sep 25, 2025

NULL pointer dereference in cstecgi.cgi in TOTOLINK N600R firmware 4.3.0cu.7866_B2022506 allows remote attackers to crash the CGI process. The request parser passes a NULL pcVar4 value to strtol when cstecgi.cgi receives an empty JSON body, dereferencing it and terminating the process. No authentication or user interaction is required, and the demonstrated consequence is a CGI-process crash that interrupts the router web service.

CVSS severity5.3
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in cstecgi.cgi in TOTOLINK N600R firmware 4.3.0cu.7866_B2022506 allows remote attackers to crash the CGI process. The request parser passes a NULL pcVar4 value to strtol when cstecgi.cgi receives an empty JSON body, dereferencing it and terminating the process. No authentication or user interaction is required, and the demonstrated consequence is a CGI-process crash that interrupts the router web service.

The record

CVE
CVE-2025-57623
Published
Sep 25, 2025
Updated
Sep 25, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2025Record 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
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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