CVE-2025-8137Public exploitNetwork attack vector

Authenticated service interruption via oversized MAC parameter

Published Jul 25, 2025 · Updated Jul 25, 2025

Stack buffer overflow in TOTOLINK A702R 4.0.0-B20230721.1521 allows remote authenticated users to interrupt service via HTTP. The /boafrm/formIpQoS handler processes an oversized mac form value without enforcing the destination buffer's bounds, corrupting stack memory. A valid sessionCheck value is required, and the published proof of concept demonstrates router denial of service rather than confirmed code execution.

CVSS severity8.8
High
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in TOTOLINK A702R 4.0.0-B20230721.1521 allows remote authenticated users to interrupt service via HTTP. The /boafrm/formIpQoS handler processes an oversized mac form value without enforcing the destination buffer's bounds, corrupting stack memory. A valid sessionCheck value is required, and the published proof of concept demonstrates router denial of service rather than confirmed code execution.

The record

CVE
CVE-2025-8137
Published
Jul 25, 2025
Updated
Jul 25, 2025
Vendor
TOTOLINK
Product
A702R
Classifications
CWE-119, CWE-120, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 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?

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

  1. Affected versionversion=4.0.0-B20230721.1521

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · A702Rversion=4.0.0-B20230721.1521

Published CVSS scores

8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.4VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499Endpoint Denial of Service

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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