rtl81xx SDK: Heap-based Buffer Overflow
CVE-2025-8302 is a high-severity heap-based buffer overflow vulnerability in rtl81xx SDK from Realtek, with a CVSS 3.0 base score of 8.8 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 rtl81xx SDK 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 | rtl81xx SDK | 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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:C/C:H/I:H/A:H. Scored by CNA (trendmicro.com).
Official description
Realtek rtl81xx SDK Wi-Fi Driver rtwlanu Heap-based Buffer Overflow Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Realtek rtl81xx SDK Wi-Fi driver. 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-26553.
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-25-879/Third Party Advisory
Other vulnerabilities in rtl81xx SDK
- 8.8 High severity
- 8.8 High severity
Recent Heap-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 9.3 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
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