CVE-2025-15356Public exploitNetwork attack vector

Authenticated router crash via unbounded sscanf

Published Dec 30, 2025 · Updated Dec 30, 2025

Buffer overflow in Tenda AC20 firmware through 16.03.08.12 allows remote authenticated users to crash the router via PowerSaveSet requests. The /goform/PowerSaveSet handler passes the unbounded time value to sscanf with four delimiter-based string conversions that omit destination-width limits. Access to the management interface and low privileges are required; denial of service is demonstrated, while code execution is reported as an undemonstrated outcome.

CVSS severity8.8
High
EPSS probability4.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Tenda AC20 firmware through 16.03.08.12 allows remote authenticated users to crash the router via PowerSaveSet requests. The /goform/PowerSaveSet handler passes the unbounded time value to sscanf with four delimiter-based string conversions that omit destination-width limits. Access to the management interface and low privileges are required; denial of service is demonstrated, while code execution is reported as an undemonstrated outcome.

The record

CVE
CVE-2025-15356
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
AC20
Classifications
CWE-119, CWE-120, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=16.03.08.0
  2. Affected versionversion=16.03.08.1
  3. Affected versionversion=16.03.08.10
  4. Affected versionversion=16.03.08.11
  5. Affected versionversion=16.03.08.12
  6. Affected versionversion=16.03.08.2
  7. Affected versionversion=16.03.08.3
  8. Affected versionversion=16.03.08.4
  9. Affected versionversion=16.03.08.5
  10. Affected versionversion=16.03.08.6
  11. Affected versionversion=16.03.08.7
  12. Affected versionversion=16.03.08.8
  13. Affected versionversion=16.03.08.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · AC20version=16.03.08.0; version=16.03.08.1; version=16.03.08.10; version=16.03.08.11; version=16.03.08.12; version=16.03.08.2; version=16.03.08.3; version=16.03.08.4; version=16.03.08.5; version=16.03.08.6; version=16.03.08.7; version=16.03.08.8; version=16.03.08.9

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 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-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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