CVE-2023-39550 in JWNR2000v2
Summary
by MITRE • 08/07/2023
Netgear JWNR2000v2 v1.0.0.11, XWN5001 v0.4.1.1, and XAVN2001v2 v0.4.0.7 were discovered to contain multiple buffer overflows via the http_passwd and http_username parameters in the check_auth function.
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Analysis
by VulDB Data Team • 01/24/2026
The vulnerability identified in Netgear JWNR2000v2 v1.0.0.11, XWN5001 v0.4.1.1, and XAVN2001v2 v0.4.0.7 represents a critical security flaw that affects multiple wireless router models within the Netgear product line. These devices are commonly deployed in residential and small office environments, making them attractive targets for cybercriminals seeking to gain unauthorized access to network infrastructure. The vulnerability manifests through buffer overflow conditions that occur when processing authentication parameters, specifically the http_passwd and http_username fields within the check_auth function. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows malicious input to overwrite adjacent memory locations.
The technical exploitation of this vulnerability occurs when an attacker submits excessively long strings through the http_passwd and http_username parameters during the authentication process. The check_auth function fails to properly validate input lengths, allowing the buffer overflow to occur and potentially corrupt program execution flow. This flaw can be leveraged to execute arbitrary code on the affected devices, effectively granting attackers full administrative control over the network router. The buffer overflow conditions create opportunities for attackers to overwrite return addresses, function pointers, or other critical memory structures, enabling privilege escalation and persistent access to the network infrastructure. The vulnerability is particularly concerning as it affects multiple device models, suggesting a systemic issue in the firmware development practices of these specific Netgear products.
The operational impact of this vulnerability extends beyond simple unauthorized access, as compromised routers can serve as launching points for broader network attacks. Once an attacker gains control of the router, they can manipulate network traffic, redirect users to malicious websites, or establish backdoors for continued access. The affected devices are commonly used in environments where network security is paramount, including small businesses and home offices, making the potential for data breaches and network disruption significant. Network administrators may not immediately detect compromise due to the subtle nature of router-based attacks, which can persist for extended periods without triggering obvious alerts. This vulnerability also aligns with ATT&CK technique T1071.004 for application layer protocol usage and T1059.001 for command and scripting interpreter, as attackers can leverage the compromised device to execute malicious commands and establish persistent access.
Mitigation strategies for this vulnerability require immediate firmware updates from Netgear, as the company has likely released patches addressing these buffer overflow conditions. Network administrators should implement network segmentation to limit the potential impact of compromised devices and deploy intrusion detection systems to monitor for suspicious authentication attempts. The vulnerability demonstrates the importance of input validation and bounds checking in embedded systems, particularly in network infrastructure devices where security is paramount. Organizations should also consider implementing network access control measures and regular security assessments to identify similar vulnerabilities in their network equipment. The affected devices should be taken offline immediately while updates are deployed, as the window of opportunity for exploitation remains open until proper patches are applied. Security professionals should also monitor for related vulnerabilities in similar network equipment, as this flaw may indicate broader firmware development issues within the affected product lines.