RT-AX88U: Use of Externally-Controlled Format String
CVE-2023-41349 is a high-severity use of externally-controlled format string vulnerability in RT-AX88U from ASUS, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 3.0.0.4_388_23748 as the first without the flaw, so updating RT-AX88U to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.86% chance of exploitation within 30 days, higher than 59% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update RT-AX88U to 3.0.0.4_388_23748 or a later version.
- Update Rt-ax88u Firmware to 3.0.0.4.388.23748 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| ASUS | RT-AX88U | before 3.0.0.4_388_23748 | 3.0.0.4_388_23748 |
| ASUS | Rt-ax88u Firmware | before 3.0.0.4.388.23748 | 3.0.0.4.388.23748 |
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
- LowA basic user account is enough.
- 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:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cert.org.tw).
Official description
ASUS router RT-AX88U has a vulnerability of using externally controllable format strings within its Advanced Open VPN function. An authenticated remote attacker can exploit the exported OpenVPN configuration to execute an externally-controlled format string attack, resulting in sensitivity information leakage, or forcing the device to reset and permanent denial of service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Externally-Controlled Format String
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
How developers prevent this class of flaw
- Choose a language that is not subject to this flaw.
- Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
- Run compilers and linkers with high warning levels, since they may detect incorrect usage.
More Use of Externally-Controlled Format String vulnerabilities (CWE-134)
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-132-7371-aecf1-1.htmlThird Party Advisory
Other vulnerabilities in RT-AX88U
- 7.2 High severity
- 7.2 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Use of Externally-Controlled Format String vulnerabilities
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.2 High severity
Spotted an error? Tell us.