CVE-2024-39803
Memory Safety in Wavlink Wl-Wn533A8 Firmware m33a8.v5030.210505
Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2024-39803 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Wavlink Wl-Wn533A8 Firmware. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 33% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Multiple buffer overflow vulnerabilities, including one in the `sel_mode` POST parameter, exist in the `qos.cgi` `qos_settings()` functionality of the Wavlink AC3000 router running firmware version M33A8.V5030.210505. These flaws allow a specially crafted HTTP request to trigger a stack-based buffer overflow, classified under CWE-120. The vulnerability carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H), indicating critical severity due to its potential for high-impact exploitation across confidentiality, integrity, and availability.
An attacker with high-privilege authenticated access (PR:H) can exploit these vulnerabilities remotely over the network (AV:N) with low complexity (AC:L). By sending a malicious HTTP request to the affected `qos.cgi` endpoint, the attacker triggers the stack-based buffer overflow in `qos_settings()`, potentially leading to arbitrary code execution, full system compromise, or denial of service, with scope expanded to changed components (S:C).
Mitigation details are outlined in the Talos Intelligence advisory (TALOS-2024-2049), available at https://talosintelligence.com/vulnerability_reports/TALOS-2024-2049. Security practitioners should consult this report for vendor-specific patch information or workarounds, such as restricting access to the `qos.cgi` endpoint or upgrading firmware if available.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-38347
Vulnerability Data
Multiple buffer overflow vulnerabilities exist in the qos.cgi qos_settings() functionality of Wavlink AC3000 M33A8.V5030.210505. A specially crafted HTTP request can lead to stack-based buffer overflow. An attacker can make an authenticated HTTP request to trigger these vulnerabilities.A buffer overflow vulnerability…
more
exists in the `sel_mode` POST parameter.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can find missing size checks before deployment.
Input validation directly enforces size checks before buffer copies.
Engineering principles require bounds checking and safe buffer handling in design.
Memory protection limits the impact of an overflow once it occurs.
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.
Secure development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.
Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.
Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.
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.
Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.
Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.
Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.
Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.
Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.