CVE-2023-0782 in AC23
Summary
by MITRE • 02/11/2023
A vulnerability was found in Tenda AC23 16.03.07.45 and classified as critical. Affected by this issue is the function formSetSysToolDDNS/formGetSysToolDDNS of the file /bin/httpd. The manipulation leads to out-of-bounds write. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The identifier of this vulnerability is VDB-220640.
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Analysis
by VulDB Data Team • 03/10/2023
The vulnerability identified as CVE-2023-0782 represents a critical out-of-bounds write flaw in Tenda AC23 routers running firmware version 16.03.07.45. This issue resides within the web interface handling mechanism, specifically in the formSetSysToolDDNS and formGetSysToolDDNS functions located in the /bin/httpd binary file. The flaw occurs when processing user-supplied data through HTTP requests, creating a condition where memory operations exceed the allocated buffer boundaries. This type of vulnerability falls under CWE-787, which specifically addresses out-of-bounds write conditions that can lead to arbitrary code execution or system compromise. The vulnerability is particularly concerning because it affects the router's web management interface, making it accessible to remote attackers without requiring physical access to the device.
The technical exploitation of this vulnerability occurs through crafted HTTP requests targeting the affected functions within the router's web server component. When a remote attacker sends malformed input data to the formSetSysToolDDNS or formGetSysToolDDNS endpoints, the application fails to properly validate the input length before writing to memory buffers. This results in memory corruption that can be leveraged to overwrite adjacent memory locations, potentially allowing attackers to execute arbitrary code with the privileges of the web server process. The ATT&CK framework categorizes this as a privilege escalation technique through software exploitation, specifically mapping to T1068 for local privilege escalation and T1566 for social engineering via web applications. The vulnerability's remote attack surface means that threat actors can exploit it from anywhere on the internet, making it particularly dangerous for home and small office networks.
The operational impact of this vulnerability extends beyond simple remote code execution, as it fundamentally compromises the integrity and security of the entire network infrastructure. Once exploited, attackers can gain persistent access to the router's management interface, potentially enabling them to modify network settings, redirect traffic, or establish backdoors for continued access. The vulnerability also represents a significant risk to connected devices, as compromised routers can serve as entry points for broader network infiltration. Network administrators face the challenge of defending against attacks that can originate from any internet-connected device, making this vulnerability particularly dangerous in environments where routers are not regularly updated or monitored. The public disclosure of the exploit (VDB-220640) increases the likelihood of widespread exploitation, as malicious actors can readily implement the attack vectors without requiring advanced technical skills.
Mitigation strategies for CVE-2023-0782 should prioritize immediate firmware updates from Tenda, as the vendor has likely released patches addressing this specific vulnerability. Network segmentation and firewall rules should be implemented to restrict access to the router's web management interface from untrusted networks, while also limiting internal access to only authorized personnel. The principle of least privilege should be applied by disabling unnecessary services and features, particularly the DDNS functionality if not required. Regular security assessments should include vulnerability scanning of network devices to identify unpatched systems, with monitoring for suspicious network traffic patterns that may indicate exploitation attempts. Network administrators should also consider implementing intrusion detection systems that can identify and alert on known exploit signatures targeting this specific vulnerability. Additionally, maintaining current threat intelligence feeds and security advisories from organizations such as the cve details and nist databases ensures awareness of related vulnerabilities and exploitation patterns that may complement the mitigation efforts for this specific issue.