CVE-2024-39802
Published: 14 January 2025
Summary
CVE-2024-39802 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 Exploit Public-Facing Application (T1190); ranked in the top 33.9% 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 are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
Multiple buffer overflow vulnerabilities, including stack-based ones, affect the qos.cgi qos_settings() functionality in the Wavlink AC3000 router firmware version M33A8.V5030.210505. These flaws arise from insufficient input validation, particularly in the qos_dat POST parameter, allowing a specially crafted HTTP request to overflow buffers and potentially corrupt the stack.
An attacker with high privileges (PR:H), such as an authenticated administrative user, can exploit these vulnerabilities remotely over the network (AV:N) with low complexity (AC:L) and no user interaction (UI:N). Exploitation triggers a scope change (S:C), enabling high confidentiality, integrity, and availability impacts (C:H/I:H/A:H), as reflected in the CVSS v3.1 base score of 9.1. The issues stem from CWE-120 (buffer copy without checking size of input).
Mitigation guidance and further technical details are available in the Talos Intelligence advisory at https://talosintelligence.com/vulnerability_reports/TALOS-2024-2049.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-38346
Vulnerability details
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 `qos_dat` POST parameter.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in router web CGI (qos.cgi) with authenticated remote access enables exploitation of public-facing application for RCE and scope-changing privilege escalation.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation of untrusted inputs like the qos_dat POST parameter to prevent buffer overflows from insufficient input checks.
Implements memory protection mechanisms such as stack canaries and non-executable stacks to block unauthorized code execution from stack-based buffer overflows.
Mandates timely identification, reporting, and remediation of flaws like these buffer overflows in router firmware to eliminate the vulnerability.