CVE-2023-37703Public exploitNetwork attack vector

Unauthenticated router crash via unchecked speed parameter

Published Jul 10, 2023 · Updated Nov 12, 2024

Stack-based buffer overflow in Tenda FH1203 2.0.1.6 allows remote attackers to corrupt memory via a crafted speed_dir request parameter. The formSetSpeedWan handler passes speed_dir through nptr to sprintf without a length check, overflowing the stack buffer v3. Network access to the HTTP management endpoint is sufficient, and the resulting stack corruption can crash the router or alter control flow.

CVSS severity9.8
Critical
EPSS probability1.11%
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 Tenda FH1203 2.0.1.6 allows remote attackers to corrupt memory via a crafted speed_dir request parameter. The formSetSpeedWan handler passes speed_dir through nptr to sprintf without a length check, overflowing the stack buffer v3. Network access to the HTTP management endpoint is sufficient, and the resulting stack corruption can crash the router or alter control flow.

The record

CVE
CVE-2023-37703
Published
Jul 10, 2023
Updated
Nov 12, 2024
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
FH1203
Classifications
CWE-787, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 12, 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?

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

  1. Affected versionversion=V2.0.1.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · FH1203version=V2.0.1.6

Published CVSS scores

9.8NIST NVDCVSS: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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1190Exploit Public-Facing Application

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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