Cyber Resilience

CVE-2023-35086

Asus Rt-Ac86U Firmware 3.0.0.4_386_51529

Published
21 July 2023
Modified
21 November 2024
CVSS Score v3.1 7.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.39 98th percentile
Risk Priority 78 floored blend · peak EPSS

Summary

CVE-2023-35086 is a high-severity Use of Externally-Controlled Format String (CWE-134) vulnerability in Asus Rt-Ac86U Firmware. Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A format string vulnerability exists in the do_detwan_cgi module of httpd on ASUS RT-AX56U V2 and RT-AC86U routers. The flaw is caused by the logmessage_normal function directly passing untrusted input as a format string to syslog and affects firmware versions 3.0.0.4.386_50460 on the RT-AX56U V2 and 3.0.0.4_386_51529 on the RT-AC86U.

A remote attacker who already possesses administrator credentials can exploit the weakness over the network to achieve arbitrary code execution, arbitrary system operations, or denial of service.

Public advisories published by TWCERT at the referenced URLs describe the issue and affected firmware but do not provide additional mitigation details beyond the CVE record. The associated EPSS score has remained at its peak value of 0.7589 since disclosure.

EU & UK References

Vulnerability Data

It is identified a format string vulnerability in ASUS RT-AX56U V2 & RT-AC86U. This vulnerability is caused by directly using input as a format string when calling syslog in logmessage_normal function, in the do_detwan_cgi module of httpd. A remote attacker…

more

with administrator privilege can exploit this vulnerability to perform remote arbitrary code execution, arbitrary system operation or disrupt service. This issue affects RT-AX56U V2: 3.0.0.4.386_50460; RT-AC86U: 3.0.0.4_386_51529.

CWE(s)
CWE-134

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-35087Same product: Asus Rt-Ac86U
CVE-2023-39240Same product: Asus Rt-Ac86U
CVE-2023-39238Same product: Asus Rt-Ac86U
CVE-2023-39239Same product: Asus Rt-Ac86U
CVE-2023-41349Same vendor: Asus
CVE-2023-28703Same product: Asus Rt-Ac86U
CVE-2023-38032Same product: Asus Rt-Ac86U
CVE-2023-39237Same product: Asus Rt-Ac86U
CVE-2023-28702Same product: Asus Rt-Ac86U
CVE-2023-38031Same product: Asus Rt-Ac86U

Affected Assets

asus
rt-ac86u firmware
3.0.0.4_386_51529
asus
rt-ax56u v2 firmware
3.0.0.4.386_50460

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent external format strings via code review, static analysis, and safe APIs.

ID.RA-01 partial match
prevents

Vulnerability identification can discover existing format-string flaws but does not prevent their introduction.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect format-string vulnerabilities before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and safe API usage that can prevent externally-controlled format strings.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify safe formatting functions and ban uncontrolled format strings.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles discourage dangerous string-handling patterns that lead to format-string issues.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly forbid the use of untrusted format strings and prescribe safe alternatives.

References