RT-AC86U: Stack-based Buffer Overflow
CVE-2023-28703 is a high-severity stack-based buffer overflow vulnerability in RT-AC86U from ASUS, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected RT-AC86U versions: 3.0.0.4.386.51255. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.89% chance of exploitation within 30 days, higher than 60% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of RT-AC86U you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| ASUS | RT-AC86U | 3.0.0.4.386.51255 | Not stated |
| ASUS | Rt-ac86u Firmware | 3.0.0.4.386.51255 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cert.org.tw).
Official description
ASUS RT-AC86U’s specific cgi function has a stack-based buffer overflow vulnerability due to insufficient validation for network packet header length. A remote attacker with administrator privileges can exploit this vulnerability to execute arbitrary system commands, disrupt system or terminate service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- twcert.org.tw/tw/cp-132-7147-afcf9-1.htmlThird Party Advisory
Other vulnerabilities in RT-AC86U
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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