CVE-2023-35086Public exploitNetwork attack vector

Administrator-authenticated code execution via syslog format string

Published Jul 21, 2023 · Updated Oct 24, 2024

Format-string injection in ASUS RT-AX56U V2 and RT-AC86U firmware allows remote authenticated users to execute arbitrary code. The httpd do_detwan_cgi handler passes the untrusted action_mode parameter through logmessage_normal and uses it as the syslog format string. Administrator access to the router web interface is required; exploitation can perform arbitrary system operations or interrupt service.

CVSS severity7.2
High
EPSS probability38.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format-string injection in ASUS RT-AX56U V2 and RT-AC86U firmware allows remote authenticated users to execute arbitrary code. The httpd do_detwan_cgi handler passes the untrusted action_mode parameter through logmessage_normal and uses it as the syslog format string. Administrator access to the router web interface is required; exploitation can perform arbitrary system operations or interrupt service.

The record

CVE
CVE-2023-35086
Published
Jul 21, 2023
Updated
Oct 24, 2024
Vendor
ASUSTeK Computer Inc.
Product
RT-AC86U
Classifications
CWE-134
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 21, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 24, 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=3.0.0.4_386_51529

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ASUSTeK Computer Inc. · RT-AC86Uversion=3.0.0.4_386_51529
ASUSTeK Computer Inc. · RT-AX56U V2version=3.0.0.4.386_50460

Published CVSS scores

7.2TWCERT/CCCVSS:3.1/AV:N/AC:L/PR:H/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.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-134Use of Externally-Controlled Format String

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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