CVE-2024-39299 in AC3000
Summary
by MITRE • 01/14/2025
A buffer overflow vulnerability exists in the qos.cgi qos_sta_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 this vulnerability.
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Analysis
by VulDB Data Team • 08/22/2025
The buffer overflow vulnerability identified as CVE-2024-39299 resides within the qos.cgi component of Wavlink AC3000 M33A8.V5030.210505 firmware, specifically within the qos_sta_settings() function. This vulnerability represents a critical security flaw that allows for arbitrary code execution through a stack-based buffer overflow condition. The flaw occurs when the device processes HTTP requests containing specially crafted parameters that exceed the allocated buffer space, leading to potential system compromise and unauthorized access to the network device.
The technical implementation of this vulnerability stems from insufficient input validation and bounds checking within the qos_sta_settings() function. When an authenticated user submits a malformed HTTP request to the qos.cgi endpoint, the application fails to properly validate the length of incoming data before copying it into a fixed-size stack buffer. This classic buffer overflow condition enables attackers to overwrite adjacent memory locations including return addresses and function pointers, potentially allowing for arbitrary code execution. The vulnerability is classified as a stack-based buffer overflow under CWE-121, which specifically addresses buffer overflow conditions occurring on the stack memory region. This type of vulnerability is particularly dangerous as it can be exploited to gain complete control over the affected device's operation.
The operational impact of this vulnerability extends beyond simple denial of service or data corruption. An authenticated attacker with network access can leverage this flaw to execute arbitrary commands on the affected Wavlink router, potentially gaining full administrative control over the device. This compromise could enable attackers to modify Quality of Service settings, redirect traffic, install malicious software, or use the device as a pivot point for attacks against other systems within the network. The vulnerability's authentication requirement does not significantly mitigate the risk as it only requires an attacker to obtain valid credentials, which may be easily discovered through social engineering, credential stuffing, or other common attack vectors. According to ATT&CK framework, this vulnerability aligns with T1078 Valid Accounts and T1566 Phishing techniques, as attackers can exploit legitimate user credentials to achieve persistent access.
Mitigation strategies for CVE-2024-39299 should prioritize immediate firmware updates from Wavlink, as the vendor has likely released patches addressing this specific buffer overflow condition. Network administrators should implement strict access controls and monitor for unusual traffic patterns or unauthorized access attempts to the affected device. The principle of least privilege should be enforced by limiting administrative access to only essential personnel and implementing multi-factor authentication where possible. Additionally, network segmentation and intrusion detection systems should be deployed to detect and prevent exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar buffer overflow conditions in other network components. The vulnerability highlights the importance of proper input validation and memory management practices in embedded systems, particularly those handling network requests from untrusted sources. Organizations should also consider implementing network access control policies that restrict direct administrative access to network devices from external networks, thereby reducing the attack surface for authenticated exploits like this one.