RTL8811AU: Heap-based Buffer Overflow
CVE-2025-8301 is a high-severity heap-based buffer overflow vulnerability in RTL8811AU from Realtek, with a CVSS 3.0 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected RTL8811AU versions: 1030.38.712.2019. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Wi-fi USB Driver to 1030.52.0325.2025 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Realtek | RTL8811AU | 1030.38.712.2019 | Not stated |
| Realtek | Wi-fi USB Driver | before 1030.52.0325.2025 | 1030.52.0325.2025 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- 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:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (trendmicro.com).
Official description
Realtek RTL8811AU rtwlanu.sys N6CSet_DOT11_CIPHER_DEFAULT_KEY Heap-based Buffer Overflow Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Realtek RTL8811AU drivers. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the N6CSet_DOT11_CIPHER_DEFAULT_KEY function. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-24786.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Heap-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the heap.
How developers prevent this class of flaw
- Pre-design: Use a language or compiler that performs automatic bounds checking.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- 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.
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
- zerodayinitiative.com/advisories/ZDI-25-880/Third Party Advisory
Recent Heap-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 9.3 Critical severity
- 9.8 Critical severity
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